Portable music player with Rating songs feature

[hablando]

Hello guys,
i am looking for a way of...
1) listening music on the go and rate songs as quickly as possible (if i could program 5 midi keys for ratings from 1 to 5 and for example by pressing button 2 to rate 2 the currently selected song)*
2) sync all the ratings with MM database
3) use those ratings with VirtualDj Software

I am on the go most of the times and i have a big music list to check and rate, that's why i try to find a way of Rating songs on the go. I don't have a problem buying an external music player (dap) as long i can rate songs easily with that player, sync ratings with MM and then use those ratings on VDJ.

*I dont know if this Rating feature could be done with the help of a Raspberry or Arduino project as well...

I hope i am not the only one trying to rate his songs in that way...