Is there any way to copy music from my Mac to my Nexus please?

I assume I can connect the two with the USB cable. However, is there a way to transfer the music over WiFi? Both devices are on my network after all.

I assume that the DRM stuff from iTunes won't work, but presumably the tunes from Amazon MP3 should be compatible? Shame we can't redownload from Amazon, as you can with music in iTunes between iDevices - or at least not in the UK.

I suppose I could upload to Dropbox or Drive but that seems a very slow process with my upload limits.

Ideas please?