I was there in January, Denmark street - never seen such a small street packed with so many music stores
Turnkey was cool (just for browsing) at all the keyboards and synths downstairs.
Wouldn't bother trying to buy something thou i stood there for a good 30mins without being served so i left.
For a great high end gear store, Nikki up at KMR is a champ! train it to Totteridge & Whetstone, then walk back up the
hill and turn left and follow that road, it'll be on the same side.
P.S don't forget to buy an all zones ticket! i did that mistake and couldnt get out of the station.
Never got out to Funky Junk, but that would probably be worth checking out for secondhand stuff.
p.s have a good time! and atleast check out abbey rd.