Yo Billy De Kid:
Don't ever record with your back to the door!!!!!
You can find volumes of epistles regarding cables for keyboards to amp and, of course, the mic cable.
I have a mid-priced Monster cable for my keyboard; it is nice.
I have a mid-priced Monster cable for my vocal mic; it is nice.
Both are better than just regular mic cables. You can spend some big $$$ for esoteric cables; I guess oxygen free cables are very good; I think Monster cables are in the oxygen free zone.
But, if your wallet can afford it, you should have a good cable for your mic and synthesizer, if you use one.
Same goes for the RCA patch cables; I found a place on the net that specialized in RCA cables, so I bought a pair; they are, indeed, good.
Don't stay up all night reading the stuff on cables; get out there and listen to some and then decide.
Green Hornet