"Instrumentals only" eliminates most of my classic rock / prog faves. I had to dig a bit, but here are some more than decent instrumental solos. Some of these tracks are more a series of solos, but them's the breaks.

Robert Fripp, Fracture https://youtu.be/ZaD7gk7BTwU

Fred Frith, Teenbeat Reprise https://youtu.be/hNhq05COL5I

Glen Phillips, Lenore https://youtu.be/lSoOqxcqyD8

Nels Cline, Blood Drawing https://youtu.be/83w2Cra1egs

Phil Miller, Green and Purple https://youtu.be/FqfaffOl3nU

Steve Hillage, Aftaglid https://youtu.be/YkPyzEmwt8c

Alan Holdsworth, Hazard Profile https://youtu.be/6zSZBAcQ-5M