For those not familiar with soundtracks/scores for Michael Mann movies, Mann almost always chooses music based on how well they serve the story and the imagery on the screen.
The songs he chooses almost always convey great mood. You won't find a bunch of corporate music samplers designed to sell units, as you do on most so-called soundtracks -- those type of albums are designed to attract consumers with big name acts, and throw in some lesser-known groups, giving them a marketing boost.
Whether it's a song with lyrics or an orchestral score, Mann doesn't choose lightly. He seems to choose with great insight, and the tracks here on "Public Enemies" are no different than his previous scores/soundtracks.
All the songs here convey the time and era (1930s, Depression-era), and are joined in between by orchestral tracks from the movie, which almost all have a sense of foreboding. The music doesn't overwhelm, and doesn't underplay the seriousness of the dramatic scenes -- they fit just right, as they don't overstay their welcome and prove just memorable enough, presenting the right sense of emotion and tension.
Anyone who likes Michael Mann movies, and appreciate his well-thought-out soundtracks, will enjoy "Public Enemies" as well.