Josef Myrow has long been my candidate for the dullest successful pop composer of the "Great American Songbook" era; he composed many songs for many Hollywood musicals, but most of them are quite bland. (Every time I would watch a '40s or '50s musical and hear a song where the melody had no distinction and didn't go anywhere, I would find it was by Myrow.) But he did manage at least one song that has stood the test of time: "You Make Me Feel So Young" from Three Little Girls In Blue. Even this song doesn't have a particularly great tune (in my opinion), but it's pleasant, and the way it keeps extending and building in excitement toward the end (taking the A section and almost turning it into a whole new song) is very good. And the lyric by Mack Gordon (an uneven but sometimes good pop lyricist of the '30s and '40s) is excellent.
Three Little Girls In Blue is a Fox musical that's rarely-seen because it doesn't have any big stars; another Fox story about three girls searching for love, it starred two of their Grable substitutes, June Haver and Vivian Blaine. But it's one of the best of the Fox musicals, because, for one thing, it's a real musical: unlike most of their other musical films, it doesn't relegate all the singing and dancing to show-within-a-show numbers. It's also one of the few musicals that Fox contractee Celeste Holm got to do for the studio, and most importantly, the first of only three films that Vera-Ellen did for the studio.
Fox's musical talent was generally inferior to that of other studios -- they rarely made musicals with anyone who was in the class of an Astaire or a Kelly or a Garland as an all-around performer -- so having a dancer of the calibre of Vera-Ellen kicks the film up a notch above most Fox product; though she doesn't do her own singing in "You Make Me Feel So Young," her dancing in the subsequent "dream ballet" (this was after Oklahoma! made dream ballets the in thing for about a decade) is at a higher level, in terms of performance, than the kind of number you usually get in one of these films.