You can examine memory consumption with tools included in the guppy module:
from guppy import hpy
hp = hpy()
hp.setrelheap()
notes = [Note(0, (1, 4)) for x in range(1000)]
h = hp.heap()
print h
Partition of a set of 11024 objects. Total size = 586364 bytes.
Index Count % Size % Cumulative % Kind (class / dict of class)
0 1000 9 124000 21 124000 21 abjad.tools.notetools.Note.Note.Note
1 1004 9 116464 20 240464 41 __builtin__.set
2 2003 18 76300 13 316764 54 list
3 1000 9 52000 9 368764 63
abjad.tools.pitchtools.NamedChromaticPitch.NamedChromat
icPitch.NamedChromaticPitch
4 1000 9 44000 8 412764 70
abjad.interfaces._OffsetInterface._OffsetInterface._Off
setInterface
5 1000 9 44000 8 456764 78 abjad.tools.notetools.NoteHead.NoteHead.NoteHead
6 1000 9 40000 7 496764 85 0x23add0
7 1000 9 32000 5 528764 90
abjad.interfaces.ParentageInterface.ParentageInterface.
ParentageInterface
8 1011 9 28568 5 557332 95 str
9 1000 9 28000 5 585332 100
abjad.interfaces._NavigationInterface._NavigationInterf
ace._NavigationInterface
<6 more rows. Type e.g. '_.more' to view.>
These results show 586K for 1000 notes.
You must download guppy from the public Internet because the module is not included in the Python standard library.