It’s fair to say millions, possibly even billions, more people have heard Arnold McCuller than have heard of Arnold McCuller.

If you’ve heard the music of Phil Collins, or Bonnie Raitt, Lyle Lovett, Aretha Franklin, Diana Ross, Bette Midler, Beck — the list goes on and on — you’ve heard Mr. McCuller.

You might even have seen him without knowing it. Delivering a powerhouse version of the national anthem, perhaps, in the movie The Sum of All Fears — for many, it was the best scene in the whole thing — or in Ry Cooder’s movie Crossroads, or a number of other films.

Most likely of all, though, you’ve heard him or seen him with James Taylor. Their musical relationship has spanned more than three decades on record and in live shows. In concert, Arnold is the guy who always takes over the vocals at the end of Shower the People, when the arrangement requires a bigger voice than JT’s.

Arnold McCuller is a great singer, if never a big star. Still, he’s got no complaints; a lot of other great singers never made it this far.

He reflected on that a little this week, talking to the Gazette in advance of his visit to Martha’s Vineyard for a performance with a second-generation Taylor, James’ son Ben, at the Whaling Church.

The first big step in Mr. McCuller’s career was when he was chosen to join the touring company of the musical Hair, back in about 1970, he said. He joined the group the same day as another singer who would later become part of Mr. Taylor’s band, David Lasley.

“David and I [were in] a group of amazing singer-songwriter friends who were in Hair. The tribe, we called it. But most of them sort of dropped it after the Broadway musical died out.

“So many of my friends had to go and get straight jobs, you know? Went back to nursing school or something.

“But David and I found more work in New York. We kept reinventing ourselves,” he said.

Sessions, bits for movies, backup singing, tours, separate bands, some songwriting, whatever they could find. And they stayed in the industry.

“I’ve always managed to pay the bills,” Mr. McCuller said. “I only ever took a side job once, in New York, when I wanted to get a better apartment, and then I ended up going on the road anyway.“ Mr. McCuller said.

Sometime in late 1976, they met James Taylor, who took their numbers and said he might call them some day. Then in 1977, he did.

Mr. Lasley, in another interview, once recalled that he was so sure someone was playing a joke that he hung up. Mr. Taylor called back.

Said Mr. McCuller: “It was the first time James went out with singers. He was living in New York then and he called David and said he wanted us to come around and talk about it.

“We ended up singing with him for six hours that day. I remember we just drank water and sang for six solid hours. We knew all his stuff and harmonized everything. It was like meeting your long-lost brother.

“The blend was just awesome. It was like the perfect marriage.”

Later the vocal group would expand to include two female singers.

“James just kept making a bigger vocal sound, choral sound on recordings,” he said.

It became one of the most stable ensembles in modern music. There have only been a couple of changes over 30 years, and of all the singers, Mr.McCuller has been the most consistent presence.

Well, you can’t work with someone for that long, essentially live with them on the road, without getting involved in their personal lives. The same year Arnold McCuller met James Taylor, James and Carly Simon had a son, Benjamin.

“So, I’ve known him since he was born,” said the singer. “I knew him probably before he was born. We’ve always been close. He calls me Uncle Arnold.”

There is much that they share. Both have benefitted by their connections to musical superstardom. Both also have sought to chart their own independent courses in music.

Mr. McCuller has recorded eight albums of his own, starting in 1984.

In 1990 he thought he’d made it when he was signed to Virgin records, and recorded an album. It was all done, up to and including the cover art, when Virgin dropped it.

“They said they didn’t think it was ‘black’” enough,” he recalled.

“That was in the years when companies were just using [albums] as write-offs I think.”

So he started his own label, What’s Good Records, with himself as its only artist. The second record, Exception to the Rule, got good airplay. Then he did a record called Back to Front, including songs he had done backing on, that he wanted to sing lead on, including work by Phil Collins, Bonnie Raitt, James Taylor, Lyle Lovett tunes, and a couple of his own.

“That got a nice review in Billboard,” he said.

His work since has enjoyed modest success.

“My latest record [Soon as I Get Paid] is my favorite because it’s a real authentic sort of blues record, with James’s band. There’s some smokin’ Mike Landau guitar on it, I didn’t do any fixing of the vocals. There’s no overdubbing. I brought in singers for a couple of tracks but it’s really very raw,” Mr. McCuller said.

And that was cathartic, for James Taylor’s material is always very tightly arranged.

“I just had to get away from that a bit,” Mr. McCuller said.

The record harks back to the music he grew up listening to in the 1950s, that his parents [who also were musicians] sang, to his blues roots. Its reception so far has been encouraging.

Also encouraging, Mr. McCuller believes, is the direction of music these days. The days of the big-label megastar is over but, he said there is still money to be made and success to be had for the canny performer.

“I think this is the new age of the singer-songwriter.

“It’s also the age of independence,” he said, citing the success of people like Bruno Mars and Ani DiFranco. “It’s the age of independent artists. That’s why Ben is doing so well.”

And so Arnold McCuller, after all the decades of being primarily a sideman, safe in the group but mostly in the background, is walking that lonesome road. No more touring as James Taylor’s or anyone else’s backup, for a while at least.

For their Sunday night gig at the Old Whaling Church, Mr. McCuller and Ben Taylor will appear as collaborators, but equals.

“We’re a double bill,” he said. “I will do three tunes, then he will do three tunes, then I will, then he will.

“We haven’t really worked out how much we’ll do together; I’ve sent him some tapes,” he said.

“The most important thing for me now is that I am at a launching point for my solo career. This is really my focus.

“So, thank you, James for a lovely 34 years, but a kid’s got to step out on his own at some point.”

Ben Taylor and Arnold McCuller are in concert on Sunday, August 14 at 8:30 p.m. at the Old Whaling Church in Edgartown. Tickets range from $40 to $75 at ticketsmv.com.