I installed all of the files/folders into C:\Users\Daniel\Documents\Arduino
There needs to be a libraries folder in the Arduino folder. It is in that libraries folder that WaveHC belongs, containing a bunch of files and folders.
and that error, variable or field 'play' declared void, is the exact error.
No, I'm sorry, but it isn't. Along with that error message is the exact name of the file that causes the error, and the line number in the file that the error occurred on. All that is important information, to me at least.
There is nothing higher than 1.0.
No major changes in the structure of the Arduino code have occurred since 1.0. There were major changes between 0023 and 1.0.
I downloaded the zip file at the top of the list in your link. I copied the WaveHC file from the zip file to C:\Users\PaulS\Documents\Arduino\libraries. I started the IDE. I pasted your code. I got one "error":
Binary sketch size: 12,606 bytes (of a 28,672 byte maximum)