I know how to create a set of pitches that moves from a to b in a linear or exponential curve.

Now, how can I get such a movement but not with a line of single pitches, but with transposed sets of pitches?

 

For example: Create movement from a4 to d4 but only with variants of (g4 a4), thus transposing the major second upwards movement until reaching (d4 e4).

May be:

 

(setf transp (gen-transition 0 7 7 1 :rounded t))
(setf set '(g4a4))
(setf out (pitch-transpose-n transp (gen-trim (length transp) set)))

SB.