en.wikipedia.org
Basically, ZDuck, you're looking for light and dark resistances. Get the datasheet for the GL5516 and check what the light and dark resistances are. Take that info to Lee's and ask them for the GL5516 or its equivalent with the same or close-enough values. Start growing your collection of datasheets...
LDR_______________ LIGHT RESISTANCE ________DARK RESISTANCE
KE-10720___________10k–20k_____________________0.5M (I got a few of these from Tayda)
9200________________10k–50k ____________________5M (I could use these, but...)
9203_________________5k–20k ____________________20M (These are what I really need!)
NSL-7532
GL5539
GL5549
NSL7530
54C679
etc
For the Pitch Witch, none of the LDRs at Lee's are appropriate. You only need 1M dark; you could try the 1k-3M and if it doesn't work well enough for your build you might find use for it in another build. Datasheet that matches dark requirement appears to be GL5528, but double-check that yourself. Also...
Consider putting together a small order of your most-needed parts and pad the order with some other common things you'll wind up using eventually in other builds such as A100k pots; 10k, 47k, 100k, resistors, jacks etc. Then you can order from another Canadian-based distributor such as A-1, Active Tech (Calgary), Avnet, BC-Robotics (Nanaimo), BJ Electric (Edmonton), Digikey (ON), Mouser (ON), etc...
It's always great to support your local brick&mortar shop, but if they don't have what you need...
