I don't know when I first heard "Happy days are here again", this Jack Yellen ditty is another sentimental song from the 1920's that belongs to my childhood. I well recollect seeing Ralf Reader's "Gang Show" (an annual get together of the Boy Scout movement) on BBC television in the mid-1950's. The version I sing can be found in 101 Pub Favourites for Buskers
With this song, my recorder and folk-music worlds overlap as I have played Happy Days Are Here Again/Tea For Two
on bass recorder quite a lot with Blue Tuesday.