1. a period of unrestrained indulgence in an activity; spree; binge: a crying jag; a talking jag.
I went on a Led Zeppelin jag about a month ago, specifically, the tune "10 Years Gone". Is it just me or is that one of the most phenomenal guitar solos ever written, the whole song actually.
I also went on a Free jag recently. My friend ruined it when he criticized me for living in the past.