This is a Lua based metronome, hence you have to extract the folder in the game/luaplayer/ folder using winzip. Do not drag drop the file in the destination folder, rather extract it to the destination folder as the script.lua needs to be in the destination folder and rest of the files need to be in the folder named "Metronome".
It has worked fine in Luaplayer V.18 and in my psp slim (2000), although i had to replace the luaplayer/Eboot.pbp with the LuaPlayerHM v3 Eboot.pbp for the V.18 to work.
If you face problems regarding lua send me an email and i will send you luaplayer and luaplayer% along with the other files so that you don't have to worry about which luaplayer to use and all you have to do is put the folders in the game folder.