Carter Alan has DJed at Boston radio stations since the late ’70s, spending the last two decades spinning classic rock on WZLX. But Alan’s love for music extends beyond the studio: To date, he’s attended 3,306 concerts, which he’s whittled down to a mere 50 for his new book The Decibel Diaries: A Journey Through Rock in 50 Concerts. We got him to air some of those memories before the book’s release on April 4 and his visit to Wellesley Books on April 6.

Do you remember your first concert? Yep. First concert was the James Gang with Joe Walsh. That’s actually in the book; that’s the first chapter. I was 16, I had a learner’s permit, and my mom actually let me have her car. It was great.

Was that first show a defining moment for you? Yeah, I mean, I went to that concert not knowing what a concert really was. I was just a tenderfoot, and I remember the first thing that really amazed me was how loud it was. You’re just not used to that. I remember being so excited at having the show play out in front of me. All I had really done before then was listen to records—and that’s great, that’s exciting, the music is awesome—but having an actual performance in front of you… In a lot of ways, yeah, I could say that that first concert really set me on my path, because it was just overwhelming. After that I tried to go to as many shows as I could.

Were there any concerts you had to sacrifice for the sake of the 50? The one show that I really wanted to include was the Jam. The Jam was more important in my evolution into punk music than some of the shows in the book—Talking Heads and the Cars and the Police. The Jam is probably the most important, because I went and saw that show at the Rat, and something clicked inside of me. I couldn’t believe it. These guys spent more time in the air than on the ground. I felt like someone who is a generation older than me might have felt seeing the Who at the Marquee back in London. [But] try as I might, I could not work it into a story. There wasn’t enough drama beyond the actual excitement of seeing the band. … The Jam is one of those bands that has been kind of lost to American history.

What’s one of the most memorable shows you ever attended, drama-wise? I think seeing Roger Waters do The Wall at the Berlin Wall back in 1990. The wall was coming down at that point, and the East Berliners were able to come across. And it was was like Woodstock. People were just walking around with their eyes [wide] like, “Oh my God.” Just seeing the East German soldiers driving their tanks and armored personnel carriers up to their side of the wall—these guys were getting out and blasting air horns and jumping up and down and dancing. I’m like, “These guys are just like us!” You know? … After the show, it just seemed like—I mean, it was idealistic to think it—but it just felt like everything was all right with the world. At least for a little while.

What about the worst show you’ve ever been to? Probably seeing Aerosmith at the Centrum in Worcester back in ’82. They were trying to come back and put out their Rock in a Hard Place album. It was a bad show. Steven Tyler did a face-plant onstage. … I wrote about that because, even though it was so bad, it was just a great way to describe or grab the true accomplishment of Aerosmith coming back, because they went all the way to the bottom. You didn’t think they’d come back. And then five years later they’ve got a platinum album and they’re all clean and sober—practically—and touring the world in the greatest rock ’n’ roll comeback in history, I think. Kind of like the Patriots.