the expansion of the record and radio broadcasting industries, professional songwriters copyrighted more than 100,000 popular tunes during this 20- year "golden age" ofAmerican songwriting. Of course, most of those ditties were flops. (Even the "giants" of the era could only count about five percent of their total output as commercially successful.) Yet the ones that hit, hit big. Royalties from recordings and sheet music of Berlin's "Alexan- der's Rag Time Band" (1911)...