Sandra Bernhard, Wednesday, November 2, at the Paramount Theatre, delivers a lot of bang for your buck. An entertainer who's already tried her hand at movies, books, stand-up comedy and television (on Roseanne, she plays the first and only recurring lesbian character to appear on a prime-time sitcom), Bernhard has just issued a new CD, Excuses for Bad Behavior, Part One, that finds her stepping confidently into the world of song. With her band, the Strap-Ons, she deftly weaves together acerbic comedy and show-stopping numbers a la Bette Midler--which means that she subverts convention while working within the mainstream. The Excuses tour finds Bernhard firing unabashed potshots at the aforementioned Midler as well as former best friend Madonna (in a hilarious satire called "Neurotica") and a bevy of other luminaries. But the real surprise, both live and on disc, is Bernhard's musical aptitude: Her soprano-cum-deadpan-rap delivery is the perfect complement to her stage repertoire, which includes Broadway tunes, a Hendrix cover and a version of "Fifty Ways to Leave Your Lover" that she manages to make her own. Bernhard is part cabaret performer, part rock star, part comedienne--and all fun.