I am fairly new to bluegrass. I started attending a local jam last fall and so far I have attended 6 jams.  I can hang with most of the rhythm playing now that I have my alternating bass strums down pretty good. I have been working on Devin's "Fill Riff's and Lead Guitar" and "Country Strumming" courses on this site which are really helpful also.  I would like to get to a place where I can start to feel comfortable with adding fills and walking bass riffs with my chord changes at the jam session. I assume if I continue to study and practice on the two courses that I mentioned above, I will finally get there.  When I am at the jam sessions some of the seasoned pickers break out with solos. That includes guitar, mandolin and banjo.  My question is when these players break out into a solo are they playing the solo completely from memory for that particular song or are they using a "bag of licks" pieced together in the key of the song in a way that aligns with the melody of the song to basically throw together a solo?   One time we were playing and the guy leading the song nodded to a banjo player to take off with a solo and the banjo player looked a little shocked like he didn't really know the song that well and he grinned, shrugged his shoulders and took off with a solo that sounded awesome.  For that reason, in that case I feel he has been playing long enough that he was able to throw together a solo using stock licks and it sounded really good for the song. What is your experience and opinions on this?  Are most solos improvised?

Thanks,

Kevin