The Pasadena Roof Orchestra was formed in Nov. 1969 by Johnny Arthy, a lover of 1920's jazz who sought to lead a dance-oriented jazz-influenced big band specializing in music from the 1923-37 period. The British band gained its name because Arthy liked the obscure song "Pasadena." The orchestra had its first gig in April 1970 and soon Arthy came across a windfall, 1, 500 original arrangements from the 1920's practically given away by an elderly lady whose father had been musical director of a dance band in the twenties. The P.R.O. started out playing once a week but, after the...