I played piano/keyboard at a very basic level when I was younger but never did any graded examinations and never really had the drive to excel at it. The bits I have picked up have helped a bit, just being able to play out your melody on a MIDI keyboard makes things a little easier, but that is all, it just gives a bit of ease, it doesn't allow you to do anything extra.
More important I'd say is having a musical ear. I come from a very musical family, where we all seem to have an aptitude for music, as I said earlier I never took advantage of this by learning an instrument but it does really help for production. Just being able to know what melodies sound good and catchy, which ones sound dull or repetitive.
On the whole I'd advise that any musical background is not essential, it can all be learnt if you're willing to put in the time and effort. In terms of improving your 'musical ear', listen to everything. Good songs, bad songs, songs from your favourite genre, songs from your least favourite. It will all help.
Hope this helps,
Harwood