I saw that question on twitter, and I thought it was be fun to discuss here. Here’s the first answer that popped into my head: Branford Marsalis’s Renaissance. I especially enjoyed his versions of “Lament” and “The Peacocks,” two tunes I really like to this day. I would listen to this album a lot while studying, and I started checking out recordings from musicians that Marsalis mentioned in the liner notes. This was basically the first album that opened me up to older forms of jazz.