Glass, Philip: ''The Photographer.'' (CBS AL 37849) After the relative conservatism of his previous CBS disc, ''Glassworks,'' this dramatic tone poem finds Glass merging orchestral textures (strings and brass) with the aggressive reeds and keyboards that dominated his music until recently. The result isn't as bold as his best work - say, ''Einstein on the Beach'' - but its combinations of instrumental and synthesized sounds are unique, and its momentum rarely flags. Don't be misled by nay-sayers who kiss off this sumptuous stuff with the too-easy ''minimalist'' label, or claim it's just a pale reflection of vague philosophical ideas. These resonant pieces are ''about'' nothing but their own energetic and terrifically imaginative sounds; even the notorious repetitions are based on the not-so-exotic notion that if something sounds lovely, let's hear it a few more times before moving on. And this music is always moving on, if you just listen closely enough. The conductor is Michael Riesman, a long-time Glass collaborator. The violin soloist is Paul Zukofsky, sounding like a country fiddler from Mars.