One glance at ''Now and Then'' and it becomes evident that this is not merely a collection of a songwriter's lyrics. The song-poems of this undisputed ''bluesologist'' triumphantly stand on their own, evoking the rhythm and urgency which have distinguished Gil Scott-Heron's career. This, the first ever collection of his poems to be published in Britain, carries the reader from the global topics of political hypocrisy and the dangers posed by capitalist culture to painfully personal themes and the realities of modern day life. His message is black, political, historically accurate, urgent, uncompromising and mature and as relevant now as it was when he started, back in the early seventies.