IMHO, better to find tunes you like than hear Pandora wander way, way, way away from what you want to hear. Trying to coerce Pandora to hunt around in surf music, or reggae, or many other areas was so frustrating I gave it up. FM? For long distance riding, why bother. After you leave your home coverage area, fiddling with tuning while riding is ...um... unwise?
Some YouTube browsing will turn up play lists, concerts, collections for anything you can think of. I'm currently obsessed with Euro-Techno (go for Worakls or N'to or the Melodic Techno Mix series) but I'm also partial to Bach, Scarlatti, etc. It's all in there. (I have large CD collection, too) There are a number of download tools to get videos or only the audio. I use Video Proc from Digiarty Software (look for a "newbie" discount) which also grabs videos. Put whatever you have onto your phone's chip, use a player app (Player Pro is good, PowerAmp is quirky but my go-to app), and rock on! (think about stepping up your chip a notch - 16G to 32G, etc.)