Tiefling's Entrancing Ballad

You briefly imbue a magical energy into musical instrument that you are proficient with, and ghostly apparitions of musical instruments appear to assist you in your performance of a specific song that you must have in mind beforehand. As long as you continue to play the instrument, and do not cease, the song will proceed as needed. If there should come a point where your instrument does not have a piece in the intended song, you must continue playing. However, only the pieces that should be played at said point will produce any sound, still in accordance with your playing.

Any Performance checks made while playing an instrument under the effect of this spell are made at advantage, or you could alternatively add an amount equal to your spellcasting modifier (minimum of 1) to the roll; this effect ends if either the caster stops playing or the magical is dispelled by an outside force.