Sideman recordings offer substantial insight into the key elements of a player’s style. Submissive to the leader, the sideman has less space to solo and, with that restricted space, must ensure their own contributions deliver the goods: if the leader has delivered their magnum opus, a weak offering on your part will probably remain committed to the master tape for prosperity. See Tommy Flanagan on “Giant Steps”*
The shorter space of time and the pressure to nail it allow us to hear a concentrated distillation of a players style. I have done this before by transcribing all of Kenny Burrell’s solos on Paul Chamber’s Bass On Top record. I am now doing the same for Sonny Rollins and have transcribed 4 of his 7 solos on Max Roach and Clifford Brown’s At Basin Street and offer some analysis at a later date. For now, please feel free to have a look and play through what has been done so far:
Gertude’s Bounce (1956)
Powell’s Prances (1956)
I’ll Remember April (1956)
What Is This Thing Called Love? (1956)
*It’s important to remember that Flanagan was an outstanding pianist of the Detroit school and under no circumstances should his legacy be his weak offering during his second or third pass on one of the most demanding works in the jazz canon.
Bobby Osborne 
I really enjoy your transcriptions!!! It should also be remembered that Coltrane, for whatever reason, had not shown the score for GS to anyone before sitting down to record, and Flanagan, thinking it might be a ballad, was furious when Coltrane counted it off at that high tempo. Flanagan was trying to play coherently while furious.
Thank you for the kind words, James! Yeah I think Coltrane was a bit sneaky with that one…perhaps he was emulating Miles’ approach to bandleading. In Lewis Porter’s biography, Flanagan says that Coltrane came ’round and played the changes for “Giant Steps” for him, and as you say he assumed it was a ballad! Have you heard the version Flanagan recorded later on? It’s great, as he always is.