r3458+Fraction:

#1 timer = timeit.Timer('Note("c'4")', 'from __main__ import Note')
   print timer.timeit(10)
   print timer.timeit(100)
   print timer.timeit(1000)
   r3458:             r3458+Fraction:
   0.0534009933472    0.0542531013489
   0.544013023376     0.549149036407
   5.43860316277      5.4941380024
   ### Fraction no faster on Note creation


#2 note = Note("c'4")
   timer = timeit.Timer('note.format', 'from __main__ import note')
   print timer.timeit(10)
   print timer.timeit(100)
   print timer.timeit(1000)
   r3458:
   0.0200870037079
   0.195698022842
   1.93302893639
   r3458+Fraction:
   0.0206418037415
   0.199695110321
   1.99831104279
   ### Fraction no faster on Note format


#3 iotools.profile_expr('Note("c'4")')
   2998 function calls (2971 primitive calls) in 0.011 CPU seconds
   r3458+Fraction:
   3086 function calls (3059 primitive calls) in 0.012 CPU seconds

#4 note = Note("c'4")
   iotools.profile_expr('note.format')
   2336 function calls (1926 primitive calls) in 0.004 CPU seconds
   r3458+Fraction:
   2410 function calls (1993 primitive calls) in 0.004 CPU seconds

#6 notes = [Note("c'4") for x in range(1)]
   Partition of a set of 921 objects. Total size = 91028 bytes.
   Partition of a set of 907 objects. Total size = 89052 bytes. (with opt)

   notes = [Note("c'4") for x in range(10)]
   Partition of a set of 8185 objects. Total size = 854628 bytes.
   Partition of a set of 7999 objects. Total size = 830012 bytes. (with opt)

   notes = [Note("c'4") for x in range(100)]
   Partition of a set of 80815 objects. Total size = 8489860 bytes.
   Partition of a set of 78919 objects. Total size = 8239524 bytes. (with opt)

   notes = [Note("c'4") for x in range(1000)]
   Partition of a set of 807116 objects. Total size = 84842352 bytes.
   Partition of a set of 788120 objects. Total size = 82334816 bytes. (with opt)

### CONCLUSION:
### Using built-in Python 2.6 Fraction in place of Abjad Fraction
### isn't any faster but does save a small but measurable amount of memory.
### Memory usage goes from 84.8M (r3458) to 82.3M (r3458 + Fraction optimization).
### This represents a memory savings of about 9.7 %.


(TEST NODE OS 10.6.4 2-core Intel iMac 1.85 GHz / 1.5 GB RAM.)
