Please help, even though it seems like a dumb question (and it is)

[superlox3]

I have a Yamaha p-85 and a M-Audio Fast Track Pro for recording.
I have a y-cord connecting them, but I've forgotten which is left and right when recording stereo.
There's a yellow cable and a red cable for plugging into the Fast Track Pro; these plug in to the front of the box.
The cable itself is a 1/4 inch Apex A206SPY cord.

Could someone please let me know which is left and which is right?

Many thanks,

-Superlox3

 

[gecko zzed]

my guess . . . red is right

 

[superlox3]

Thanks a ton!
I really appreciate the help!

-superlox3