Even if you don't own a single jazz record and think that Miles Davis might play for the Knicks, you've heard the hearty horn of Maynard Ferguson. That's him giving all on his trumpet in "Gonna Fly Now," the ubiquitous theme from Rocky. And even though his film and TV work probably reached more ears than his straight-jazz efforts (well, except for his "disco version" of the Rocky II theme), the 77-year-old Canadian native has performed a litany of styles with a career stretching back to a 1950 debut with Stan Kenton's big band. Ferguson is at his best fronting a band, as he does with BBN. Never a critic's darling for his commercial slant, Ferguson nonetheless has wowed live audiences by reaching for his trademark "double high C" notes and tutoring jazzbos ranging from Chuck Mangione and Chick Corea to Joe Zawinul and Jaki Byard. And though age has understandably taken a toll on his blowing powers, he retains much spark thanks to his "yogic concentration," the breathing practice he learned in India in the late '60s. Too bad the Beatles fled the Maharishi just before he arrived Ė the White Album could have used a few more horns.