I've got music on an external hard drive which mounts happily. It also opens as a folder window though, which I don't want it to do. I'm sure there's a very simple preference to change this but the only ones I can find are to do with CDs etc.
Main Menu>System Tools>System Settings>System Section>Details>Removal Media
Check "Never prompt or start programs on media insertion"
No CD, no DVD, no usb stick, no media will start automatically, only will be mounted.
LM17.1 Cinnamon (PC) and Mate 17.1 (Notebook) with AMD Catalyst
HP Pavilion g4-1316br, AMD Quad Core, 1,5 GHz, Radeon 6520G/7450M,
Linuxcounter Registered User #506065 (2008)