If you’ve got a massive music library, better think twice about syncing it with iTunes Match: the maximum size of an iTunes library in the iTunes Match beta is 25,000 songs. Assuming a library in which song is an average of 4 minutes long and compressed in CD quality 320kbps, that basically means the upper limit on a library is a size of 250 gigabytes. That’s pretty generous for a $24.99 a year service.