''R&B now is a lot different from R&B in the past,'' says producer, writer, and multi-instrumentalist Bryan Loren. ''In the '60s, R&B was Motown, and that was considered pop. I like to think of myself like that-covering all bases.'' In his short career, Loren, 25, has already covered a lot of the bases, although behind the scenes. His smooth, bouncy style of pop-R&B-nurtured in Philadelphia when he was a teenage session man and played with the band Cashmere-has already been heard on records by Sting (''We'll Be Together''), Whitney Houston (Loren wrote ''Feels So Good,'' the B side of her hit ''I'm Your Baby Tonight''), and R&B acts like Shanice Wilson (page 23). On the recommendation of his friend Michael Jackson, Loren wrote, produced, and played most of the instruments on last year's ''Do the Bartman'' novelty hit. Unfortunately, all of the dozen or so tracks Loren and Jackson worked on for Jackson's Dangerous album were shelved. Loren admits to being disappointed by that but feels he'll get even when Arista releases his new solo album, Music From the New World, in March. ''When people hear my stuff, they'll question Michael's common sense,'' he says, adding with a laugh, ''if I have my way, 1992 will make him very regretful.''
