Whether it is a mind bending virtuosic display or a subtle and understated artistry, a solo calls upon the soloist to be in the spotlight.
It’s like someone hogging the spotlight in a conversation. One could be flashy or understated in this: “I’ve been to all these places! Cancun was probably the best but Iceland was great too and how could I forget Italy! I have to tell you about one time…” or “Yeah I’ve been to a couple places. Mt. Everest was alright. We made it to the top in one piece, I guess that’s something. Paris, I don’t know if that counts, but I went there last year and…”
What do the other players do? Politely back up this rambler. That is all we can do when someone goes on a tangent: “Interesting”, “Cool”, “Yeah”, “No”, “Explain”. It leaves no give and take. This is not a conversation. It’s egotistical preaching. That’s banal and boring.
Some of the best “soloists” aren’t even really soloing at all. They are listening. They are attuned to everything around them and responding. These musicians know when to say something and when to back out entirely to let something interesting happen.
The best conversations are those which don’t have a definite “leader”. Everyone is contributing in a way that it feels natural. A great improvising group is just like that. Everyone is contributing in a way that feels natural.