music21.clef

This module defines numerous subclasses of Clef, providing object representations for all commonly used clefs. Clef objects are often found within Measure objects.

Clef

class music21.clef.Clef(**keywords)

A Clef is a basic music21 object for representing musical clefs (Treble, Bass, etc.)

Some clefs only represent the graphical element of the clef, such as G clef, which is subclassed by TrebleClef() and FrenchViolinClef().

>>> tc = clef.TrebleClef()
>>> tc
<music21.clef.TrebleClef>
>>> tc.sign
'G'
>>> tc.line
2

Most clefs also have a “lowestLine” function which represents the diatonicNoteNum of the note that would fall on the lowest line if the Clef were put on a five-line staff. (Where C4,C#4,C##4,C-4 etc. = 29, all types of D4 = 30, etc.)

>>> tc.lowestLine
31

Equality

Two Clefs are equal if their class is the same, their sign is the same, their line is the same and their octaveChange is the same.

>>> c1 = clef.PercussionClef()
>>> c2 = clef.NoClef()
>>> c1 == c2
False
>>> c3 = clef.TrebleClef()
>>> c4 = clef.TrebleClef()
>>> c3 == c4
True
>>> c4.octaveChange = -1
>>> c3 == c4
False

Note that these are not equal:

>>> clef.TrebleClef() == clef.GClef(line=2)
False

Clef bases

Clef read-only properties

Clef.name

Returns the “name” of the clef, from the class name

>>> tc = clef.TrebleClef()
>>> tc.name
'treble'

>>> tc = clef.Treble8vbClef()
>>> tc.name
'treble8vb'

>>> tc = clef.MezzoSopranoClef()
>>> tc.name
'mezzoSoprano'

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

Clef read/write properties

Clef.octaveChange

The number of octaves that the clef “transposes”, generally 0.

>>> tc = clef.TrebleClef()
>>> tc.octaveChange
0
>>> clef.Treble8vbClef().octaveChange
-1

Read/write properties inherited from Music21Object:

Clef methods

Clef.getStemDirectionForPitches(pitches: Pitch | Sequence[Pitch], *, firstLastOnly: bool = True, extremePitchOnly: bool = False) → str

Return a string representing the stem direction for a single Pitch object or a list/tuple/Stream of pitches.

>>> P = pitch.Pitch
>>> bc = clef.BassClef()
>>> bc.getStemDirectionForPitches(P('C3'))
'up'

For two pitches, the most extreme pitch determines the direction:

>>> pitchList = [P('C3'), P('B3')]
>>> bc.getStemDirectionForPitches(pitchList)
'down'

If firstLastOnly is True (as by default) then only the first and last pitches are examined, as in a beam group. Here we have C3, B3, C3, so despite the B in bass clef being much farther from the center line than either of the Cs, it is stem up:

>>> pitchList.append(P('C3'))
>>> bc.getStemDirectionForPitches(pitchList)
'up'

If firstLastOnly is False, then each of the pitches has a weight on the process

>>> bc.getStemDirectionForPitches(pitchList, firstLastOnly=False)
'down'

If extremePitchOnly is True, then whatever pitch is farthest from the center line determines the direction, regardless of order. (default False).

>>> bc.getStemDirectionForPitches(pitchList, extremePitchOnly=True)
'down'
>>> pitchList.insert(1, P('C2'))
>>> bc.getStemDirectionForPitches(pitchList, extremePitchOnly=True)
'up'

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

Clef instance variables

Clef.line

The line, counting from the bottom up, that the clef resides on.

>>> clef.AltoClef().line
3
>>> clef.TenorClef().line
4

May be None:

>>> print(clef.NoClef().line)
None
Clef.sign

The sign of the clef, generally, ‘C’, ‘G’, ‘F’, ‘percussion’, ‘none’ or None.

>>> alto = clef.AltoClef()
>>> alto.sign
'C'
>>> percussion = clef.PercussionClef()
>>> percussion.sign
'percussion'

Note the difference here:

>>> clef.Clef().sign is None
True
>>> clef.NoClef().sign
'none'

Instance variables inherited from Music21Object:

TrebleClef

class music21.clef.TrebleClef(**keywords)

The most common clef of all, a treble clef.

>>> a = clef.TrebleClef()
>>> a.sign
'G'
>>> a.line
2
>>> a.lowestLine
31
>>> note.Note('E4').pitch.diatonicNoteNum
31

TrebleClef bases

TrebleClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

TrebleClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

TrebleClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

TrebleClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

BassClef

class music21.clef.BassClef(**keywords)

A standard Bass Clef

>>> a = clef.BassClef()
>>> a.sign
'F'

BassClef bases

BassClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

BassClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

BassClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

BassClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

AltoClef

class music21.clef.AltoClef(**keywords)

A C AltoClef, common for violas.

>>> a = clef.AltoClef()
>>> a.sign
'C'
>>> a.line
3

AltoClef bases

AltoClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

AltoClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

AltoClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

AltoClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

Bass8vaClef

class music21.clef.Bass8vaClef(**keywords)

A rarely used Bass Clef an octave higher.

>>> a = clef.Bass8vaClef()
>>> a.sign
'F'

Bass8vaClef bases

Bass8vaClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

Bass8vaClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

Bass8vaClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

Bass8vaClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

Bass8vbClef

class music21.clef.Bass8vbClef(**keywords)

A bass clef configured to be an octave lower.

>>> a = clef.Bass8vbClef()
>>> a.sign
'F'
>>> a.octaveChange
-1

Bass8vbClef bases

Bass8vbClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

Bass8vbClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

Bass8vbClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

Bass8vbClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

CBaritoneClef

class music21.clef.CBaritoneClef(**keywords)

A Baritone C clef (as opposed to an F Baritone Clef)

>>> a = clef.CBaritoneClef()
>>> a.sign
'C'
>>> a.line
5

CBaritoneClef bases

CBaritoneClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

CBaritoneClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

CBaritoneClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

CBaritoneClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

CClef

class music21.clef.CClef(**keywords)

A generic C Clef, with no line set

>>> a = clef.CClef()
>>> a.sign
'C'

CClef bases

CClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

CClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

CClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

CClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

FBaritoneClef

class music21.clef.FBaritoneClef(**keywords)

an F Baritone Clef

>>> a = clef.FBaritoneClef()
>>> a.sign
'F'
>>> a.line
3
>>> b = clef.CBaritoneClef()
>>> a.lowestLine == b.lowestLine
True
>>> a.sign == b.sign
False

FBaritoneClef bases

FBaritoneClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

FBaritoneClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

FBaritoneClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

FBaritoneClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

FClef

class music21.clef.FClef(**keywords)

A generic F-Clef, like a Bass clef

>>> a = clef.FClef()
>>> a.sign
'F'

FClef bases

FClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

FClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

FClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

FClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

FrenchViolinClef

class music21.clef.FrenchViolinClef(**keywords)

A G Clef that appears in many old French Violin scores, appearing on the lowest line, and thus higher than a treble clef.

>>> a = clef.FrenchViolinClef()
>>> a.sign
'G'
>>> a.line
1

FrenchViolinClef bases

FrenchViolinClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

FrenchViolinClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

FrenchViolinClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

FrenchViolinClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

GClef

class music21.clef.GClef(**keywords)

A generic G Clef

>>> a = clef.GClef()
>>> a.sign
'G'

If not defined, the lowestLine is set as a Treble Clef (E4 = 31)

>>> a.lowestLine
31

GClef bases

GClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

GClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

GClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

GClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

GSopranoClef

class music21.clef.GSopranoClef(**keywords)

A G clef on the middle line, formerly occasionally used for soprano parts.

>>> a = clef.GSopranoClef()
>>> a.sign
'G'
>>> a.line
3

GSopranoClef bases

GSopranoClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

GSopranoClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

GSopranoClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

GSopranoClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

JianpuClef

class music21.clef.JianpuClef(**keywords)

Jianpu notation does not use a clef, but musicxml marks it with a specialized “jianpu” sign.

>>> jc = clef.JianpuClef()
>>> jc.sign
'jianpu'

JianpuClef bases

JianpuClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

JianpuClef read/write properties

Read/write properties inherited from Clef:

Read/write properties inherited from Music21Object:

JianpuClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

JianpuClef instance variables

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

MezzoSopranoClef

class music21.clef.MezzoSopranoClef(**keywords)

A C clef with C on the second line. Perhaps the rarest of the C clefs

>>> a = clef.MezzoSopranoClef()
>>> a.sign
'C'
>>> a.line
2

MezzoSopranoClef bases

MezzoSopranoClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

MezzoSopranoClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

MezzoSopranoClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

MezzoSopranoClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

NoClef

class music21.clef.NoClef(**keywords)

represents the absence of a Clef.

>>> nc = clef.NoClef()
>>> nc.sign
'none'

Note that the sign is the string ‘none’ not the None object

>>> nc.sign is None
False

NoClef bases

NoClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

NoClef read/write properties

Read/write properties inherited from Clef:

Read/write properties inherited from Music21Object:

NoClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

NoClef instance variables

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

PercussionClef

class music21.clef.PercussionClef(**keywords)

represents a Percussion clef.

>>> pc = clef.PercussionClef()
>>> pc.sign
'percussion'
>>> pc.line is None
True

Percussion clefs should not, technically have a “lowestLine,” but it is a common usage to assume that in pitch-centric contexts to use the pitch numbers from treble clef for percussion clefs. Thus:

>>> pc.lowestLine == clef.TrebleClef().lowestLine
True

  • Changed in v7.3: setting octaveChange no longer affects lowestLine

PercussionClef bases

PercussionClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

PercussionClef read/write properties

Read/write properties inherited from Clef:

Read/write properties inherited from Music21Object:

PercussionClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

PercussionClef instance variables

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

PitchClef

class music21.clef.PitchClef(**keywords)

Superclass for all other clef subclasses that use pitches.

PitchClef bases

PitchClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

PitchClef read/write properties

PitchClef.octaveChange

The number of octaves that the clef “transposes”, generally 0.

>>> tc = clef.TrebleClef()
>>> tc.octaveChange
0
>>> clef.Treble8vbClef().octaveChange
-1

Changing octaveChange changes lowestLine (but not vice-versa)

>>> tc.lowestLine
31
>>> tc.octaveChange = 1
>>> tc.lowestLine
38
>>> tc.octaveChange = -1
>>> tc.lowestLine
24

Read/write properties inherited from Music21Object:

PitchClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

PitchClef instance variables

PitchClef.lowestLine

The diatonicNoteNumber of the lowest line of the clef. (Can be None)

>>> clef.TrebleClef().lowestLine
31

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

SopranoClef

class music21.clef.SopranoClef(**keywords)

A soprano clef, with C on the lowest line (found in Bach often)

>>> a = clef.SopranoClef()
>>> a.sign
'C'
>>> a.line
1

SopranoClef bases

SopranoClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

SopranoClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

SopranoClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

SopranoClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

SubBassClef

class music21.clef.SubBassClef(**keywords)

An F clef on the top line.

>>> a = clef.SubBassClef()
>>> a.sign
'F'

SubBassClef bases

SubBassClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

SubBassClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

SubBassClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

SubBassClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

TabClef

class music21.clef.TabClef(**keywords)

represents a Tablature clef.

>>> a = clef.TabClef()
>>> a.sign
'TAB'

TabClef bases

TabClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

TabClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

TabClef methods

TabClef.getStemDirectionForPitches(pitchList: Pitch | Iterable[Pitch], *, firstLastOnly: bool = True, extremePitchOnly: bool = False) → str

Overridden to simply return ‘down’ for guitar tabs.

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

TabClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

TenorClef

class music21.clef.TenorClef(**keywords)

A C Tenor Clef, often used in bassoon and cello parts and orchestral trombone parts.

>>> a = clef.TenorClef()
>>> a.sign
'C'
>>> a.line
4

TenorClef bases

TenorClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

TenorClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

TenorClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

TenorClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

Treble8vaClef

class music21.clef.Treble8vaClef(**keywords)

A treble clef an octave up (such as for piccolos)

>>> a = clef.Treble8vaClef()
>>> a.sign
'G'
>>> a.octaveChange
1

Treble8vaClef bases

Treble8vaClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

Treble8vaClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

Treble8vaClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

Treble8vaClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

Treble8vbClef

class music21.clef.Treble8vbClef(**keywords)

A vocal tenor treble clef. Also for guitars.

>>> a = clef.Treble8vbClef()
>>> a.sign
'G'
>>> a.octaveChange
-1

Treble8vbClef bases

Treble8vbClef read-only properties

Read-only properties inherited from Clef:

Read-only properties inherited from Music21Object:

Read-only properties inherited from ProtoM21Object:

Treble8vbClef read/write properties

Read/write properties inherited from PitchClef:

Read/write properties inherited from Music21Object:

Treble8vbClef methods

Methods inherited from Clef:

Methods inherited from Music21Object:

Methods inherited from ProtoM21Object:

Treble8vbClef instance variables

Instance variables inherited from PitchClef:

Instance variables inherited from Clef:

Instance variables inherited from Music21Object:

Functions

music21.clef.bestClef(streamObj: stream.Stream, allowTreble8vb=False, recurse=False) → PitchClef

Returns the clef that is the best fit for notes and chords found in this Stream.

>>> import random
>>> a = stream.Stream()
>>> for x in range(30):
...    n = note.Note()
...    n.pitch.midi = random.randint(70, 81)
...    a.insert(n)
>>> b = clef.bestClef(a)
>>> b
<music21.clef.TrebleClef>
>>> b.line
2
>>> b.sign
'G'

>>> c = stream.Stream()
>>> for x in range(10):
...    n = note.Note()
...    n.pitch.midi = random.randint(45, 54)
...    c.insert(n)
>>> d = clef.bestClef(c)
>>> d
<music21.clef.BassClef>
>>> d.line
4
>>> d.sign
'F'

This does not automatically get a flat representation of the Stream.

There are a lot more high notes in a (30) than low notes in c (10), but it will not matter here, because the pitches in a will not be found:

>>> c.insert(0, a)
>>> clef.bestClef(c)
<music21.clef.BassClef>

But with recursion, it will matter:

>>> clef.bestClef(c, recurse=True)
<music21.clef.TrebleClef>

Notes around middle C can get Treble8vb if the setting is allowed:

>>> clef.bestClef(stream.Stream([note.Note('D4')]))
<music21.clef.TrebleClef>
>>> clef.bestClef(stream.Stream([note.Note('D4')]), allowTreble8vb=True)
<music21.clef.Treble8vbClef>

Streams of extremely high notes or extremely low notes can get Treble8va or Bass8vb clefs:

>>> clef.bestClef(stream.Stream([note.Note('D7')]))
<music21.clef.Treble8vaClef>
>>> clef.bestClef(stream.Stream([note.Note('C0')]))
<music21.clef.Bass8vbClef>
music21.clef.clefFromString(clefString, octaveShift=0) → Clef

Returns a Clef object given a string like “G2” or “F4” etc.

Does not refer to a violin/guitar string.

>>> tc = clef.clefFromString('G2')
>>> tc
<music21.clef.TrebleClef>
>>> nonStandard1 = clef.clefFromString('F1')
>>> nonStandard1
<music21.clef.FClef>
>>> nonStandard1.line
1
>>> nonStandard2 = clef.clefFromString('D4')
>>> nonStandard2
<music21.clef.PitchClef>
>>> nonStandard2.sign
'D'
>>> nonStandard2.line
4

>>> tc8vb = clef.clefFromString('G2', -1)
>>> tc8vb
<music21.clef.Treble8vbClef>

Three special clefs, Tab, Percussion, and None are also supported.

>>> tabClef = clef.clefFromString('TAB')
>>> tabClef
<music21.clef.TabClef>

Case does not matter.

>>> tc8vb = clef.clefFromString('g2', -1)
>>> tc8vb
<music21.clef.Treble8vbClef>

>>> percussionClef = clef.clefFromString('Percussion')
>>> percussionClef
<music21.clef.PercussionClef>

>>> noClef = clef.clefFromString('None')
>>> noClef
<music21.clef.NoClef>

Invalid line numbers raise an exception:

>>> invalidClef = clef.clefFromString('F6')
Traceback (most recent call last):
music21.clef.ClefException: line number (second character) must be 1-5;
            do not use this function for clefs on special staves such as 'F6'

Can find any clef in the module

>>> clef.clefFromString('Treble')
<music21.clef.TrebleClef>
>>> clef.clefFromString('trebleclef')
<music21.clef.TrebleClef>
>>> clef.clefFromString('treble8vb')
<music21.clef.Treble8vbClef>