Why would you hold a phone to listen to music??? You listen to music in your car and its in landscape because you use navigation on it and switching between the two would be ridiculous, or surfing the web in landscape, texting in landscape then having to multitask to a flipping portrait app, thats ludicris. I've never met a single person that has any problems or hassle with playlists, Apple's library is extremely engaging and can't be beat, I'm not seeing the point here. At least Apple gets this right with their native music app that supports landscape for browsing my music(beautiful cover flow) but thats Apple, I'm sorry I guess only big companies know how to make something that suits more than ones taste.
This was only a suggestion but as with most devel's they never want to hear what a potential customer wants only what they think is wrong for correction. This app is a solution to a non-existent problem or caters to an extremely small portion of confused users.