LOUISVILLE, NOV. 4 -- First he made music with Hal David, then Carole Bayer Sager. Now Burt Bacharach is striking chords with Vinnie Moscarelli, a West Virginia horse breeder.

Bacharach, acclaimed songwriter, and Moscarelli, modest horseman, have collaborated on a racy number to perform outdoors Saturday at Churchill Downs. The joint production is Soul Of The Matter, a colt conceived in Chesapeake City, Md., born in Charles Town, W. Va., and headed for the richest race in North America, the $3 million Breeders' Cup Classic.

With a $1.56 million purse and $78,000 breeder's bonus awaiting the winner, Bacharach had a shameless hope today: May the horse be sharp.

Eleven years since he gave up an entire tour to follow Heartlight No. One, his champion filly, Bacharach is following a somewhat different course with Soul Of The Matter. He said he's not so absorbed this time. He'll fulfill his commitment to conduct the Fort Wayne Symphony tonight, take a private plane here (compliments of pal Merv Griffin) for Soul Of The Matter's afternoon race, then fly to Fort Wayne for another evening performance.

"If he wins that race, it'll be a heck of a ride back and a heck of a concert," Bacharach said today from his Indiana hotel. "I may try to bring the horse with me."

When Bacharach ended his business relationship with Fred Braunstein in the mid-1970s, he needed a new outlet for his thoroughbreds. Braunstein had played polo with Moscarelli, and introduced the trainer to Bacharach. An alliance formed: Moscarelli found a 75-acre farm in Charles Town, and he and Bacharach pooled their broodmares. They co-own the farm, which Moscarelli and his wife, Suzanne, dubbed "Country Roads." "Credit John Denver," Vinnie Moscarelli said. "We must have heard that song five times as we were looking for a place."

The location drew disbelief in horse-breeding circles. "We're always having to defend our location," Suzanne Moscarelli said. "But you can do your thing wherever you are." The brighter prospects raised at Country Roads are sent to trainer Dick Mandella in California; the lesser ones are sold or go to Delaware Park, where Moscarelli and son Vincent train about 20.

In the spring of 1990, the Moscarellis sent Soul Light to Northview Stallion Station in northeast Maryland for a union with freshman sire Private Terms, Wood Memorial winner and Kentucky Derby favorite of 1988. On an April day the next year, Suzanne Moscarelli pulled a near-black colt from the heaving mare (who hasn't foaled since) at Country Roads.

"I kept telling Burt, 'We've really got a nice colt, and we're going to send him {to California} so you can see him run,' " Vinnie Moscarelli said. "I want to tell you what kind of man Burt Bacharach is. His son Christopher, seven years old, had soccer practice, and Burt had promised he'd go watch. He never saw the race."

Soul Of The Matter won his debut at Santa Anita by four lengths a year ago despite a wide trip, which so moved jockey Kent Desormeaux that he placed a call to the Westminster, Md., home of Charlie Hadry, the man who'd trained Private Terms. An ecstatic Desormeaux told Hadry that Soul Of The Matter looked like Private Terms, strode like Private Terms, made wind rush like Private Terms.

This March, Soul Of The Matter delivered a stunning defeat to juvenile champ Brocco in the San Felipe Stakes. After a fifth place in the Kentucky Derby, he got four months to rest his ailing feet, and since is 2-for-2. His most recent win was his richest, the Super Derby at Louisiana Downs.

"I'm almost glad I'm not in Louisville," Bacharach said. "This {concert} is a good diversion. It forces me to behave, instead of being caught up in the hysteria like I was before the Derby. It's crazy."