"Midnight Express." Sound track. Casablanca. Before buying old titles in CD, it's wise to listen again to the LP or cassette version of an album to make sure the music stands up. This is especially true of albums whose appeal rested in large part on technology--as in the synthesizer-based tension on this 1978 sound track. Giorgio Moroder's music was a terrific pop breakthrough at the time, but it now seems tame next to advances in his own efforts, including "Cat People" with David Bowie, and works, such as Jan Hammer's "Miami Vice," that were influenced by Moroder's musical tension.