Sound not smooth on Android with Spotify

Hi,
I’m running djay on my Nexus 4 with Android 5.0 and only play songs from spotify with wifi connection. My problem is, that from time to time the sound is not smooth - it gets stuck for some fractions of a second. This judder/jerking unfortunately is enough to make it impossible to use djay for my dance class…
I have the problem with different songs, however not always at the same time and there can be minutes without these lags.
Thanks in advance for your help!

it seems to be an issue with the music speed, because i usually play the tracks at slower speeds. But as this is the key feature of djay for me help would really be appriciated…