Two weeks ago, we posted the first part of our conversation with MacArthur Award-winning alto saxophonist Miguel Zenón, who has selected tenor saxophonist Mario Castro to join him as part of The Jazz Gallery Mentoring Series. Their first performance of four was well-received, and we're looking forward to hearing the chordless quartet again on Thursday, July 17th, 2014 , as they continue to refine their two-horn ensemble sound.Here's our conversation with Castro, who, like Zenón, hails from Puerto Rico and is a Berklee alumnus (Zenón is class of '98; Castro graduated in 2011):The Jazz Gallery: When did you first meet Miguel?

Mario Castro: I met Miguel for the first time at a jam session he did in Puerto Rico. He used to go every December and do some jam sessions with the purpose of bringing up the musician community, and I met him at one of those sessions. It must have been like 2004 or 2005.

TJG: What do you recall of that meeting?

MC: At the first jam session, I got really sick—I think it was because I was really nervous—and at the second, I got to play with him. The third one got cancelled, but at the fourth one I got to talk to him for a while. He talked to me about sound and about the importance of knowing vocabulary, of having substance when I play; he told me, “You gotta develop this, that…you gotta develop a repertoire.”And I remember he looked at me in the eyes and asked, “Are you serious about this?” And I said, “Yes.” So he said, “Okay, if you want to learn for real, you have to leave Puerto Rico and try to expand.” At that time, I feel like "jazz education" in Puerto Rico wasn’t as developed as it is maybe now. The conservatory has a program and they bring in all different artists, and I feel like that happened so quickly thanks to Miguel and David [Sánchez] and people who, you know, had an urge to bring education there.

TJG: Did you keep in touch with while at Berklee?

MC: Oh yeah, I bother him a lot—I used to. I mean, I still do: by email, ask him about recordings, send him recordings. “What do you think?” you know? Just ask him any type of question. I want to give him space and everything, but actually I always felt like he was a role model. He is a role model for me and somebody who I want to follow, and I’m interested in his opinions.

TJG: Aside from Miguel, did you have any other mentors during your time at Berklee?

MC: In terms of teachers, Hal Crook was a slap to my face. It was great, and it was very motivating. I also had this amazing ear training teacher who passed away two or three years ago named Steve Prosser, and basically he was expanding your concept of hearing where the one is in the key [the root of a tonality], and he would make us write every week at least eight bars of modal composition that would be based out of that mode. We would discuss how it sounds, and he would go in deep, like talking about emotion, which is something I love. It was the first time I heard a teacher at Berklee talking about music like, “Can you see it? Can you see the fire?” I was like, “Exactly!” I feel like that’s the way of learning for me, so he helped me out.

TJG: You graduated from Berklee in 2011. How has working professionally changed your outlook as an artist?

MC: I noticed that the things that used to be important to me have broadened. I’m trying to think of myself as a musician and as a person in the world instead of just at an institution.When you’re in an institution and you’re there absolutely every day—80% percent of when you’re awake is hanging or talking or playing—it’s like living in one world, and when you move out there are all these other new things. Music is important, but I’m pretty sure there’s other things that are important to me. While I was at school, it was all about that and obsession—the more obsessed the better.

TJG: You already have quite a bit of professional experience leading your own quintet and composing for various configurations, including quintet plus string quartet. What are you most looking forward to in these next couple weeks working with Miguel?

MC: I’m very interested in seeing, first of all, how Miguel plays my stuff, and I’m looking forward to seeing him in action because I know he’s basically a machine of destruction when it comes to reading and remembering music. I really want to absorb from him the ability of absorbing music and understanding it so quickly—that’s something I’m going to be looking forward to.The more most honest mistakes I make, the better. This is the moment. This guy has been playing with all of these organizations—SFJazz, that’s such a complex ensemble—and he has so much experience and knows so much music. I’m curious to see how he organizes himself as well. So, yeah: everything.

TJG: Were you surprised when you got the call?

MC: Actually, when he told me about this, I was ready to ask him, “Hey man, I’m trying to straight up learn from you, and if you’re ever in town and you need help, I mean, I’ll paint the house! As long as I can hear what you have to say about music and listen to music together.”

Miguel Zenón & Mario Castro perform at The Jazz Gallery on Thursday, July 17th, 2014. The band features Zenón on alto saxophone, Castro on tenor saxophone, Ricky Rodriguez on bass, and Henry Cole on drums. Sets are at 9 and 11 p.m. $15 general admission, $10 for Members, and free for SummerPass Holders. Purchase tickets here.