Sure, it’s dance music so it can’t be too wild. But Duke Ellington, Benny Goodman, Count Basie. These guys had varied songs that included (limited but real) imp

Sure, it’s dance music so it can’t be too wild. But Duke Ellington, Benny Goodman, Count Basie. These guys had varied songs that included (limited but real) improvisation, differing tempos, etc. But really the OP article is about lyrics and I think it’s safe to say that the songs sung by Ella Fitzgerald, Nina Simone, Billie Holiday, Frank Sinatra, and Nat King Cole were more complex than top 40 pop today mostly is.