Last month I also watched MGM's 1942 classic For Me and My Gal starring Judy Garland and Gene Kelly. This was a nostalgic story of a vaudeville duo preceding and during World War I. Both Garland and Kelly (in his film debut) were in top form, although there was not as much dancing as I would have liked (despite being directed by Busby Berkeley). This was a more plot-driven musical than many, and some of the scenes (like Kelly deciding to injure himself to avoid the draft) were pretty weighty for a musical.
I liked the World War I-themed numbers (which must have conjured up fond memories for the audience of the last war), but the title song takes the cake:
Courtesy of spearsboy01 on YouTube
Watch the movie and I guarantee you will be wishing you could buy some war bonds!