Hamish Teaches the World to Sing

After many top-billed singers at the much-anticipated Christmas Karaoke fest were struck down in their prime, Hamish gallantly stepped into the breach with a hitherto unequalled repertoire.

On marvelling at this the Regulars realised that their long-held suspicions may indeed bear true and Hamish was, in fact, the 6th Nolan; only prevented from performing on stage with the others due to the proliferation of his facial hair.

This unprecedented discovery inspired the regulars to research this further where, to their delight they found further confirmation of this with Hamish appearing under his stage name of 'Max':

http://uncyclopedia.wikia.com/wiki/The_Nolan_Sisters