In terms of reunions, the Tijuana Brass would probably never have ranked up there with the Beatles. But in 1966 the Brass outsold the Beatles two to one, and though the Beatles set as well as sold a few records, they never did match the Brass' having five albums in the Top 20 at the same time.

So when Herb Alpert broke up the Brass in 1969, there was a little moaning in the record libraries of the world -- but not much. Which makes the warm reaction to their reunion 15 years later surprising even to Alpert.

"We had a chance to play at the Greek Theatre in Los Angeles during the Olympics, and I thought I was just going to do two concerts and that would be it," Alpert recalls. "I'd get the guys together, play those concerts and move on. It seemed like a fun thing to do because of all the people from the different parts of the world being in Los Angeles at that moment.

"So I was just going to do the Greek and call it," he says, "and I was swamped with requests from promoters around the country to play different venues. I thought as long as it's going to take me three weeks to a month to get the band in shape just to play two concerts, I might as well do a few more." The tour, which kicked off with a concert for Olympic athletes in Shrine Auditorium at the University of Southern California, has since stretched to 40 dates, including the Merriweather Post Pavilion tomorrow.

Lest anybody think Alpert needs the gig, all you have to know is that he's the A in A&M Records, the ones with the Police, Go-Go's and Joe Jackson on their roster. The M is Jerry Moss, and 23 years ago neither would have dared to predict they'd be heading one of the top 10 record companies in America.

It was the Bull, of course, that started it all. Alpert, a Los Angeles native who started playing trumpet at age 8, had become a session player, occasional producer (the first Jan and Dean session resulted in "Baby Talk" in 1959, and Dante and the Evergreens' "Alley Oop") and writer ("Wonderful World," a big hit for both Sam Cooke and Herman's Hermits).

But Alpert and Moss wanted to make their own records and have their own company. Which they set up in a small garage. "We released a record prior to 'Lonely Bull' on another label called Carnival. We put up $100 apiece for that record, and then we turned it over for distribution to another company. And with the money that they gave us, we recorded 'The Lonely Bull' and released that on A & M."

It wasn't quite that simple, of course. Another friend had written a song called "Twinkle Star," and that's what Alpert and Moss had in the can. Unable to find the exact sound they were looking for, they took a break and headed for nearby Tijuana, where they killed some time by going to a bullfight.

Good career move.

Layering the American pop melody with Mexican rhythms -- as well as some authentic bullfight crowd noises recorded on the scene -- Alpert transformed "Twinkle Star" into "The Lonely Bull." It was different from anything else then on the radio and promptly went to number one. The band, which was really just a bunch of studio musicians, took its name from the site of the inspiration.

Still, the odds of continuing success were phenomenally stacked against A & M and, in fact, the next few Tijuana Brass albums didn't sell all that well. What kept everything together was a pack of gum. To be specific, Teaberry Gum. As in the Teaberry Shuffle.

"That really helped a lot," Alpert concedes. "I don't know if that was the catalyst, but it certainly didn't hurt. After 'The Lonely Bull,' there was somewhat of a lull -- the records didn't catch on the same way 'The Lonely Bull' did. I did an album called 'South of the Border,' and on it was the 'Mexican Shuffle' tune. I got a call from the ad agency handling the gum account and they wanted to use it as the centerpiece for a commercial. So I agreed to arrange it for them, and with that exposure people started to hear that sound and got more accustomed to the Tijuana Brass sound."

Accustomed enough to buy 75 million copies of 18 Tijuana Brass records. In the 1960s alone, the group sold 45 million albums (a figure surpassed only by the Beatles and Elvis Presley).

But despite tours and television specials, Alpert broke up the Brass in 1969, reuniting it briefly in 1974 for a command performance for the queen of England. On a subsequent tour he billed the group as TJB, because some of the original members had left and the music had less of the Ameriachi sound.

How long the latest reunion (with five original members) will last, Alpert won't estimate, but it may be longer than he had originally planned. "As a group we've never played in Latin America, and the records have done quite well through the years there, so I'm tempted to take a tour down there. And we've had offers to play in Japan and Europe as well, so I'm just going to see what happens."

He's also released a new Tijuana Brass album, hopefully (and just a bit subliminally) titled "Bullish." The title cut is already getting some air play, though even Alpert admits "it's tough out there, espcially for instrumentals. There are very few that get played."

Particularly when so many of his artists are hogging precious air time. How does the boss feel about that? "I like that, it's a great challenge," he insists. "And it's always a challenge to come up with an interesting instrumental that radio will play. They are few and far between. The last big one was probably Herbie Hancock's 'Rockit,' and before that, the one I had back in 1979, 'Rise.' "

Although he did a short tour with African trumpet player Hugh Masakela in 1978, Alpert has pretty much abandoned a regular touring cycle. Heading up a successful record label keeps him out of trouble -- he's particularly involved with A & M's recording facilities and Latin division, as well as with looking for artists.

"Producing records, that's where my strength and instincts are," he says. "I'm not crazy about the everyday, in-the-trenches work -- that just doesn't appeal to me," though it was enough to make him a millionaire by the mid-'60s. "We were putting out good records," Alpert says.

"That's the common demominator then and it is again now. We almost sunk in 1979. There was a little bit of a lull in the industry in general, and we went from independent distribution to being distributed by RCA, so that transition was rough for us. But we kept at it and our artist roster pulled us through."

Family pulled him through as well. In the mid-'70s he looked to his own roster and found true love with Lani Hall, who had been the lead singer in Sergio Mendez's Brasil '66. Hall has continued her recording career (on A & M) and will do a segment at the Post Pavilion. So, too, may Aria, the Alperts' 9-year-old daughter.

"She just started dancing to 'Bullish' when we were recording the tune in the studio and she approached me to see whether she could dance in the show. This was not my idea," says Alpert, who admits he embraced the idea with more than a bit of trepidation.

"I didn't want her to be on display, and I didn't want it to seem like I was trying to catch everyone's sympathies by having my 9-year-old daughter dancing. It's just a nice way to travel."