What is trick bag?

Trick bag is a term used in blues music to refer to a collection of tricks, licks, and techniques that a musician uses to improvise during a performance. It is essentially a musical toolbox containing different techniques that a musician can use to keep their music fresh and interesting. A trick bag may include things like bends, hammer-ons, pull-offs, slides, vibrato, and other techniques that can be used to add character and expression to a performance. The term "trick bag" can also refer to a specific song or riff that uses a particular musical trick or technique as its central theme.