During a DJ-set I select music from my collection which fits best for providing an interesting dancing experience. I try to catch the mood of the moment by observing the dancers and translate this feedback into the tanda. My tango collection is quite vaste and in high resolution for best sound perception.
I play mainly from the Guardia Nueva and Epoca de Oro repertoire but there are no limitations, everything is possible. If I feel that a newer song fits the moment and it’s dancable I play it.
In my opinion it is very important to provide a variation in musical style between the tandas and to develop a tanda flow for having an enjoyable milonga.