A selection of some of Jack’s songs on YouTube. If you like those, you can see more at the full YouTube Channel
(see footnote below about “A.L.Lambert”):

Note: in some of the older videos at the YouTube Channel, you may notice references to A.L.Lambert. This is because Jack is the same guy named Adam who used to bill himself as A.L.Lambert. However, in an effort to avoid any association (or legal trouble) with the super-famous guy who shares that name, he is going by his long time nickname ‘Jack’ (or ‘Brother Jack’) these days.