Since I recently upgraded to SSD, I've always sacrificed it for capacity. I ran DaisyDisk to see how my old drive was distributed and iTunes turned out to take up about 35GB of space (about 20-25GB of them are Podcasts and iTunes U lectures from Stanford). I googled a way to transfer my iTunes library to an external HD. It saved me a lot of space apparently, but I realized that my external drive is slow (5400 rpm) and even though iTunes takes merely 1 second to start up, it still takes time to load data from my external drive. So I wondered to myself, if I could somehow use 2 different iTunes libraries? (one is for my music and movies - which is not much, and the other one is for my Podcasts and iTunes U - which is a lot and I don't use them regularly). I tried a solution by holding down the alt/option key when opening iTunes, but I wasn't sure if it was gonna add the entirely new library, or allow me to add a secondary library? Please clarify for me. Thanks.