From my point of view, I don't really care too much for solos on instruments that aren't mandolin, piano, electric guitar, and lyre, as they are the most flexible in game (not saying solos on other instruments aren't good, i just prefer those four because of how much you can do). Solos on cello and violin usually sound empty or like some notes are being missed (probably because the octaves hadn't been set right), but they're amazing on jams.