Is Michael McDonald cool again? The singer-songwriter (and his fabulous head of hair) returns to Philly

Since the mid-1970s, Michael McDonald has crooned and cooed his way into our senses with a rich, soulful manly baritone unlike any other. If you could create a sonic model based on fine, aged whiskey being poured into thick hot caramel, you'd come up with McDonald's vocal éclat. Away from the recording and touring circuits for almost a decade, McDonald returned  with 2016's Last Waltz tribute tour dedicated to The Band. Then there was a co-composition with hip, nu-model R&B bassist Thundercat, and now a buoyant new album, Wide Open, for which he wrote or cowrote nearly every tune. He plays  the Merriam Theater on Friday. We caught him running through an airport for this interview.

The good hair gene! [Laughs] That was my old man, who had the greatest hair in the whole family.

Everybody's career is marked with periods where things seem to happen more often, and other times where you just keep trudging a road, staying in the game. That is, until you get excited about a project, or become part of a good one. I always tell my son, 'If you want to make a living, get used to saying yes, do as many things as you can, because you never know when doors will open and close. These are creative opportunities.' I look at the Doobie Brothers, and that's a band that keeps the engine purring by touring and staying on the road in good times and bad.

Walter's death was blindsiding. We knew he had health struggles, but not to that extent. He was a private guy. I liked him as a person. He was a kind guy [with]  such as wicked, sardonic sense of humor. Of all the feats he accomplished — his iconic musical prowess, songwriting abilities — I'll remember that he was always kind. In this business, you notice those things.

I just liked all the guys on that tour, was a big fan of The Band, and that last live gig of theirs was legendary, worth reliving, We all thought it was a privilege to be asked to be part of it. To play that book of songs was a real joy, especially when we got tighter.

The biggest thing for me is being on much better behavior than I used to be. I don't drink or smoke, and I sleep as much as I can, which is not that easy on tour. A good solid five hours works for me. It's mostly what I don't do that saves my voice.

I am a big fan of this whole new sound because Solange and Thundercat are bringing a jazz element into it, which is natural and inherent. R&B is where jazz came from, so it's nice to feel that evolution happening again. Thundercat is an amalgam of his influences — Jaco Pastorious, Stanley Clarke — yet he is his own invention. Plus, he's brought that jamming into a composer's place. He's writing songs. And he never sleeps or puts that bass down. I admire that he is always creating. I'm so the opposite way. You have to cattle-prod me to do the next thing.

It was fascinating how it happened. Kenny was responsible for that. Loggins' kids came to him, and my kids, too — they love the guy — when Thundercat mentioned Kenny and I in an interview. Kenny took the initiative, contacted his manager, and said he'd love to write something with both of us. It was very free.

That song is a metaphor for a more general feeling, this scenario of men and women. At 65, I'm thinking I'd like to run into the end zone one more time — that surprises me, as I didn't think I'd feel that way at this age, the feeling of being here and wanting to compete, say something. So I used that old "Hail Mary pass" analogy.  I didn't think I'd be touring and making records at 65. I figured I'd be relaxing and watching television.

I dug the idea that we might be able to play it live with that deep groove, but I loved the words. They resonate. And I'm not so foreign to social awareness in song. I sneak them in, say like "Taking It to the Streets." You're right, though, I normally stick with love and human nature. That's my wheelhouse.