Recent Android devices that run official firmware versions will only support MTP for file transfers. (I am aware Cyanogenmod et al support USB mass storage. I run CM myself. However replacing the device firmware as out of scope for this discussion) When transferring music from Rhythmbox to a Nexus 7 device, this error is repeated for *every song* that is transferred: LIBMTP_Send_Representative_Sample(): could not get object info. The songs are actually transferred successfully.. it's just that you will develop RSI from clicking "Close" on dialog box windows by the time your whole collection has transferred. Bug reports date back to 2010 on the GNOME bug tracker, and there's a couple on Launchpad too from years ago. The issue appears to exist for many Android devices. Can the community suggest an alternative music manager that supports MTP devices that works cleanly? -Toby (Every few years I think "Surely Linux on the desktop is good enough for non-hackers", then the moment you give it to someone who isn't a hacker, it falls apart. Transferring music is a simple task, and works perfectly under Apple and Microsoft host operating systems.)