How do swingdjs find the next song to play?

A dj always thinks: What would be a perfect song to play after this one? I always get some association between the songs.

Often the songs are played in the same style of swing, for example if it is played by a big band I'll continue with another song played by a big band. Other styles may be Kansas city style or a soft style like Oscar Peterson trio.

Other times it is an instrument that gets my attention, "Yeah, the trumpet is this song is sooo cool, lets have more trumpets". So I maybe transition from Louis Armstrong to Harry James.

It can also be a musician, lets say I just played a song with Gene Krupa, I know he also played with Benny Goodman, so then I play a song with one of Benny Goodmans small groups.