Par COBHAM BILLY. When he burst onto the international stage in 1971 with the Mahavishnu Orchestra, Billy Cobham had already recorded with Miles Davis and dozens of others. But it was his otherwordly playing with Mahavishnu that redefined what was possible on the drum set. Cobham's first solo album, 1973's Spectrum, became a number one hit, spawned three future jazz standards, and cemented his pla…