"Bessie Smith, St. Louis Blues" is a classic example of the Blues genre. Here are some Blues elements you can hear in the song:
12-bar blues chord progression: The song follows a standard 12-bar blues chord progression, which is a common feature of Blues music.
Call and response: The lyrics and melody are structured in a call-and-response format between the lead vocalist and the band, which is another common element of Blues music.
Soulful vocal delivery: Bessie Smith's powerful, emotional vocal delivery is characteristic of the Blues genre. She uses a lot of vibrato, melisma, and other vocal techniques to convey the feeling of the song.
Blues scale: The melody and solos in the song are based on the Blues scale, which consists of the root, flat third, fourth, flat fifth, fifth, and flat seventh notes of the major scale.
Use of blue notes: The use of blue notes, which are microtonal notes that fall in between the pitches of the standard major scale, is another hallmark of the Blues genre.