"just standard ones"
Okay, they vary in cost from $1.58 each upt $2.79 each (and you are talking a large qty, correct?)
They vary in size, they vary in home much resistance they have when illuminated to when light vs dark.
As the maxim chips are kind of pricey it seems, perhaps a design that is better suited to creating a digital on/off signal would better.
This part is not bad, $1.58 unit, should drop with qty.
Light-on resistance is 4-11K, with a 100K pullup resistor to 5V, the low voltage out should be
5V*11,000/(11,000+100,000) = 0.495V which would be a good logic low.
As the light starts going away, once the resistance gets to 20K should see a logic high
5V*20,000/(20,000+100,000) = 0.833V.
Now if you have a bunch of shift registers such as
which are $0.31 each and have 8 inputs, you can read in long words and then use software to go thru and find the bit that changed to represent the note/tone/sound whatever.
As a hardware guy, I prefer the method I started describing, where you read the data from a specific location, but that is coming from a speed required background. That way you need 17 chips for 256 bits.
Using inexpensive shift registers, you need 32 chips to read the same bits.
The other thing I also consider in one-off projects is how much wiring is needed. Obviously you will be spending more time just connecting +5 & Gnd to all the additional chips, mounting 2x the wirewrap sockets (lot easier to fix mistakes or tweak the design that way), etc.
For a layout, you could have 2 chips on a board with the pullup resistors & a decoupling cap and 2 leads off to each of 16 photoresistors assuming you will need the photoresistors spread out every couple of inches along the maze path (or laid out in a big matrix where the maze could be re-layed out in any manner),build up as many as you need for the amount of photoresistors you use. Then spread the boards out some, with the +5/Gnd, data latch, and shift clock signal coming from a central point to all boards and data in/out daisychained along. Then you could split up the assembly work also.
Or maybe someone has shift-in register boards built like these already and you just need to add your photoresistor and pullup resistor.
If you're trying to keep costs down, I would suggest something like the RBBB
that you could assemble yourself as well (won't take long).
The jeenode takes an arduino and organizes the output into ports, then you get some plug in modules to different things.