Music Video/Airplay/Airport Express combo

If I play a music video purchased on iTunes on my iPhone or iPad Music App and do airplay to my Airport Express, it plays the music video audio to the Airport Express.

If I use Remote app on iPhone or iPad tied to my iMac's iTunes Library and use Airplay from iTunes, it will send only "songs" to the Airport Express, but will switch to playing video and audio on my iMac for that song (nothing to Airport Express), then back to Airport Express audio for any subsequent "songs".

I tried seeing if I could go into options to see if I could ask it to play like a song (and not a video), but no such luck. Tried making it into an AAC version, not even an option. Is there a way to be able to tell it to play like a song? It would be nice to put a setting on the playlist that says to play all music videos like a song.

Any help here is greatly appreciated.