we have the wanderer's minuet play an audio queu when its fully charged, but for mage's ballad you just got to keep looking at your guage or one of the two abilities affected by it to know when it proced and you can use the ability again. i suggest that at least at the mage's ballad we get an audio queu to know when to use those abilities (blood arrow or rain of death) in other to maximize dps's with that song.