Circular Breathing

You begin carefully regulating your breath so that you can continue playing longer, or keep breathing longer in adverse conditions. 

You can maintain concentration on this cantrip in addition to another spell. If you lose concentration on another spell while concentrating on this cantrip, you also stop concentrating on this cantrip. While maintaining concentration on this spell you can breathe underwater, and you can cast spells using verbal components and bardic performances that would normally require breathable air. In addition, you have advantage on saving throws against gasses and adverse atmospheres.

The number of minutes you can maintain concentration on this spell increases by 1 when you reach 5th level (6 minutes), 11th level (7 minutes), and 17th level (8 minutes).