Recently, hubby and I listened to IHR podcast #64, where there is an amazing section on compression. He plays a recording of big band w/ scat singer, and then the scat singer's voice disappears in the mix. He explains the settings he used, and it totally brought out the parts of the singing that were buried.
We also subscribe to some old radio show podcasts, and I was left wishing the person who puts out the "case closed" series knew how to apply compression to those old shows. We were listening to a Sam Spade episode, and the music just buries his voice, right at the climax of the story! (what a shame) Also, there was a part with an elderly woman's voice in the scene, and the pitches were so high and inconsistent, it was very difficult to make out her words.
I don't know if a lot of people already know about the IHR podcasts, but I'm really glad for them. Just wanted to share about that.
Good luck on your project!