Possible Clues:

• Old bar material
• 'The Entertainer' musical genre
• When there was a scrap of two for time, by the sound of it
• And all that jazz from E. L. Doctorow
• American name, said to be composer
• Bestseller that became a musical
• Jazz artist with good voice, perhaps rising
• Style Fats Waller used
• I'm great (anag.)
• Music paper accompanying magazine