Music app iOS 8.4 number of songs

WWhilst I seem to be avoiding some of the library corruptions of music some are having since new iTunes and iOS I have noticed a strange anamoly. On both iPad and iPhone if I go settings - general - about the number of songs stored in my device has a habit of fluctuating between 985 and 1020. It will report one number for a good while, then switch to the other. bit odd, anyone else seeing this? Other than that the music app appears to be working fine - I have skipped apple music and continue to remain an old school 'match' customer