def abstraction():
a = NoteSeq("C4. Eb8")
a1 = a.transp(5).stretch_dur(0.5)
a2 = a.inv("Db''")
a3 = a1.inv(8)
A = a + a1 + a2 + a3
A2 = A.transp(2)
B = a1.transp(8) + a1.transp("Eb''")
c = NoteSeq([Note(x.value, dur=0.125) for x in a + a1])
C = (c.inv("Ab''") + c.inv(10) + c.stretch_inverval(2).transp(2) +
c.inv("G''") + c.inv("E''").stretch_inverval(1) +
c.inv("A").stretch_inverval(1))
a4 = a.stretch_dur(2).inv(6)
Part1 = A + NoteSeq("C2") + A2 + B
Part2 = C + a4
midi = Midi(1, tempo=90)
midi.seq_notes(Part1 + Part2, track=0)
midi.write("midi/abstraction.mid")
