My favorite headcannon is that Jack has an amazing singing voice and he doesnt even know it.
One day when they’re driving in the car, Bitty has his Sappiest Love Songs Ever playlist going, and Jack’s hitting every note in If I Ain’t Got You. By now Bitty knows Jack can sing, so he posts a video of Jack just going at it on his twitter. The offical Falcs account retweets it. Lin-Manuel Miranda retweets it. Bad Bob retweets it with a “He definitely got that one from his mother”. #WhatThePuckZimmermann is trending #1. The world absolutely loves that this big, quiet, awkward hockey bro also belts it out to sappy love songs on long drives, and Bitty is so proud they finally get to see a part of the real Jack.