If you have a series of crotchets (quarter notes), and you want to effect an approximate ritardando by using tempo markings, which of the following would sound more natural:
Arithmetic Progression: decrease tempo by a fixed value for successive crotchets, e.g. 100, 90, 80, 70; or
Geometric Progression: either decrease tempo by a applying a fixed ratio of the previous tempo for successtive crotchet, .e.g 100, 90, 81, 73; or alternatively decrease tempo by a fixed value for a geometrically increase duration, e.g. for crotchets 1,2,4,8, use tempo 100, 90, 80, 70?
NB: For context, this is used as a workaround to achieve a rit effect during playback for some sequencers.