Duke Ellington, Glenn Miller and Judy Garland were all at the top of their game and the charts. Fred Estaire had a nice run in the 1930s and Count Basie established his dominance.
Most people did not have televisions, so the radio was the primary source of entertainment throughout the decade. And radio wasn’t exactly like it is now, where DJs play song after song after song. Radio was filled with entertainment of all sorts: stories, poetry, news, live music, variety shows and more.
Songs in the 1930s were sometimes more popular than the artist. It wasn’t strange for a song to become popular by one artist, and then re-done by another artist a month later. Because of this, we tend to focus on the songs more than the artists who performed them, because often times the song was popular and performed by several artists.
Music from the 1930s was generally upbeat and sometimes very relaxing. Humor was an important element in popular music.