The two-CD set Old Friends: Live on Stage, recorded during five dates on Simon & Garfunkel's we-needed-the-cash reunion tour, suggests the pair has become a little hazy after all these years. ''America'' still gets whoops from the crowd, and an Everly Brothers guest spot (on ''Bye Bye Love'') is fun. But the mellow new arrangements don't always suit the duo's spirited hits, ''The 59th Street Bridge Song (Feelin' Groovy)'' is missing, and the whiff of commercialism hangs in the air like the pot smoke of old.

