This war-time gem is as fluffy as you'd expect: the plot is thin, the relationships are cliche'd, and the acting is pretty much by-the-book. But it's also a heck of a lot of fun, and the musical numbers are top-notch.
You've got a homely, backwoods circus performer named Daisy (Judy Canova) who is more than a little stupid, and her equally dim-witted and goofy boyfriend Pinky (Jerry Colonna) who trains pigeons and dabbles in magic. Daisy and Pinky provide the slapstick, and boy to they dish it out. In Pinky's case it works -- he knows when to be subtle and when to stop a gag -- but Daisy comes off as sloppy and her timing is a little off. I'll give her this, though: she can look like a man when she needs to.
Meanwhile, at the base, Stephen (played by Alan Jones) is the romantic lead and the excuse to bring in musical numbers: he's a former Hollywood producer and is trying to put on a show...you know, those shows featuring amateurs and shoddy sets until the opening night 3 days later, when everybody is a pro and the sets are gorgeous. His love-interest is Vicki Marlow (Ann Miller), the worldly and wise daughter of the General.
The plot itself isn't all that important: gangsters want to kill Daisy, Stephen wants to put on a show featuring Daisy and Vicki, but to keep Daisy on the base he needs to disguise and protect her (from medical doctors and hooch dancers), and to get Vicki into his show he needs to woo her (which is one of the more bizarre moments in the movie: Ann goes from disliking him to loving him in the space of about 2 seconds, and his method of pitching woo seems to be to insult a girl) What is important are the occasionally inspired comic routines and the snappy songs, not to mention Ann's breathtaking taps.
The highpoints -- for me -- were the two Ann numbers ("Jitterbug Lullabye," a sweet and clever song & dance duet, and a percussive solo where she taps, claps, types, and twirls along with a machine gun and a wall-clock. This is possibly the most enjoyable and relaxed tap number I've ever seen her do: it's technically brilliant but not so frantic that her sense of fun is obscured), and the final "Wacky For Khaki," wherein Judy more-or-less drops the bumpkin twang and shows us that she really CAN sing AND be funny.
The comedy treads some familiar ground but does have it's moments: Pinky's magic tricks and odd banter are delightful, and Ann's deadpan delivery is great as well. This all comes together in a somewhat anti-climactic ending. And the army looks like a really fun place. "True to the Army" is exactly what it was meant to be: fluffy patriotic fun with great songs and distinctive leads. View it in that light and you'll have a great time.