The real question here is what do you consider loops?

Thanx to Tangmo I recalled Acid Planet and my feeble attempt at using acid audio loops. I found acid type audio loops very limiting. I still do today. The only acid type audio loops I use today are percussion loops like shakers, tambourines, and occasionally drums.

BUT a lot of string instrument software uses loops. For instance a number of guitar strumming programs use loops, i.e. press a key or two and get a guitar strumming said chord.

https://www.applied-acoustics.com/strum-gs-2/library/

https://realitone.com/products/realibanjo

https://www.kirkhunterstudios.com/products/kinetic-string-motion-engine/

and NI Session Guitars just to name a few. Plus you can save either the audio and/or the MIDI output on many of these.

How about MIDI drum loops? There are a ton of them out there. Plus there are MIDI loops for a lot of instruments available from a number of companies.

So when we are talking loops we must specify exactly what kind of loops we are talking about. In fact I call RTs intelligent loops, both the audio and the MIDI side of them.

YMMV

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64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware