Songs imply sequencer contents, which may use preset or user styles, maybe easy record with panel memories and pads, or maybe multitrack like a midi file, press one button and listen...
Styles imply composer or custom contents, with panel memory registrations, but not necessarily any song to go with them, thus you'll have to twiddle your fingers with styles...
Song style would imply a style geared towards an accurate arrangement of a well known standard.
To complete the circle, style song might be a stylish song, but described with poor grammar