“MUTUAL ATTRACTION.” Sylvester. Warner Bros. Disco may be dead, but Sylvester’s allegiance to it isn’t. One listen to “Sooner or Later” or “Someone Like You” and you’ll be smack-dab back in the late ‘70s, boogie-ing your little keister off. This kind of song sounds good on the dance floor or in an aerobics class. But unless you spend an awful lot of time going for the burn, so to speak, you may be immune to their appeal. Few artists are as stubbornly resistant to musical change as Sylvester--even the Gershwins’ “Summertime” is given fast-paced, work-up-a-sweat treatment. One of the few cuts on “Attraction” that varies from form is the evocative, samba-laced “Cool of the Evening,” on which the San Francisco-based singer keeps his charged-up, dance-floor delivery in check. Sylvester’s really not bad when he looks to sources other than disco for inspiration.