table( r=2^((-24...24)/12) ,  440 r, note_names)
#  ratio to A440     freq (Hz)		note
# - - - - - - - - - - - - - - - - - - 
   0.25              110		A2
   0.26487           116.54094
   0.28062           123.47083		B2
   0.2973            130.81278		C2
   0.31498           138.59132
   0.33371           146.83238		D3
   0.35355           155.56349
   0.37458           164.81378		E3
   0.39685           174.61412		F3
   0.42045           184.99721		
   0.44545           195.99772		G3
   0.47194           207.65235
   0.5               220		A3
   0.52973           233.08188		   A#
   0.56123           246.94165		B3
   0.5946            261.62557		C3 (middle C on piano)
   0.62996           277.18263		   C#
   0.66742           293.66477		D4
   0.70711           311.12698		   D#
   0.74915           329.62756		E4
   0.7937            349.22823		F4
   0.8409            369.99442		   F#
   0.8909            391.99544		G4
   0.94387           415.3047		   G#
   1                 440		A4
   1.05946           466.16376
   1.12246           493.8833		and so on.
   1.18921           523.25113
   1.25992           554.36526
   1.33484           587.32954
   1.41421           622.25397
   1.49831           659.25511
   1.5874            698.45646
   1.68179           739.98885
   1.7818            783.99087
   1.88775           830.6094
   2                 880
   2.11893           932.32752
   2.24492           987.7666
   2.37841           1046.50226
   2.51984           1108.73052
   2.66968           1174.65907
   2.82843           1244.50793
   2.99661           1318.51023
   3.1748            1396.91293
   3.36359           1479.97769
   3.56359           1567.98174
   3.7755            1661.21879
   4                 1760