It's the little intro he plays before 'Make It Mine' on his latest Live album. I got
from RKOP. His official fan forum. All credit goes to user 'Blane' for posting this.
Listen to the song for the strumming patern. It's quite easy.
[ Tab from: http://www.guitaretab.com/j/jason-mraz/204959.html ]
e|---------------------------------10----------------------------|
B|--5--7--8-----8--10--12-----12--------7----7--8--5---3---5-----|
G|---------------------------------------------------------------|
D|---------------------------------------------------------------|
A|--3--5--7-----7--9---10-----10---9----5----5--7--3---2---3-----|
E|---------------------------------------------------------------|