No, but you can store the music files on the SD card - some users have reported problems with the unit recognizing some 4GB cards, but others have no problems. The Garmin website states that it supports up to 2GB cards.
Internal Space: The Zumo's internal storage capacity is 1.9 GB, although a good portion of that is used for pre-installed maps, TTS voices and the like. But even if you excluded the not inconsiderable amount of space left, you can always use...
External Space: The Zumo's empty SD slot means you can populate it with whatever size card is available and that its operating system will recognize. Although 8GB is the largest size SD card made I've never heard of anybody using one in a Zumo (or any other GPS) -- mainly because at present it is the worst GB/per dollar deal available (i.e., disproportionately and factually expensive). Accordingly I and many others use a 4GB SD card in our Zumoes.
How many MP3s will a 4GB card hold? Well, most songs are anywhere from 2.5 to 4.5 MBs. We'll say 3.5 MB as an average and to do the calculation. If you divide 1,000 MBs (i.e., 1GB) into segments of 3.5 MB songs, you'd end up with have 285.7 MP3 songs per each 1 GB! Further, if you had the 4GB card you could multiply that number of MP3 songs by 4. That would mean you would be able to fit 1,142 MP3 songs on a single 4GB SD card! That translates roughly into more than 100 11-song CDs!!!!
So uh, would 1,142 MP3 songs or 100 CDs in your Zumo be enough music for you.....??? YEAH BABY!!!
Well, the picture is an exaggeration of course; but you know what I mean.
Actually let's have even MORE fun: given the numbers I supplied above, if each of the 1,142 songs was 3 minutes* long the Zumo holds enough music to ride from San Francisco to New York and NEVER HEAR THE SAME SONG TWICE!!** Er, and when you get tired of those you could always just switch to XM!!