rfi : timestretching

Here's the relevant section from the AKAI S950 manual: (note how they explicitly use altering drum loops as an example--and the S950 was released in 1988!)

Timestretch is a facility that allows you to either lengthen or shorten a sample without changing that samples pitch over a factor of 999% (i.e a one second sample can be stretched to a maximum length of nearly 10 seconds). There are many uses for this technique. Firstly, it is possible to change the tempo of a sampled drum loop without changing its pitch. Alternatively, it is possible to change the pitch of the drum loop and then change it back to its original tempo. It can also be used to lengthen samples so that, as you go higher up the keyboard, the sample length remains constant. It is also possible to lengthen or shorten backing vocals which could be 'spun in' in an extended remix.

Oh yes I'd forgotten about that one. The setting I mentioned earlier was 'cyclic' (not 'constant'). Recommended in the manual for use on notes of constant pitch rather than anything with rhythm or changing pitch, but actually gives the classic time stretched spoken ragga vocal effect (with high percentage).

out of curiosity, does anyone know when Cubase came along & the impact that had?

Cubase came out around 1989, I think, on the Atari ST. Although other systems were just as (if not more) powerful (eg Emagic/C Lab Notator - the forerunner to Logic and used by 4Hero), Cubase enabled a more visual/graphic approach to programming beats and copying patterns. Actually there were already programs that offered a broadly similar approach (eg Master Tracks Pro and Performer) but they were not popular in Europe.

Where Cubase had an additional impact was in the cracked copies that became widely available. This and the prices of 2nd hand Atari STs dropping through the floor as professionals changed platform c.1993-95 opened up music production to a lot of people who would previously not have had access to it.