I've enjoyed playing some of those "room escape" games on my phone, so I decided to build my own [low-tech] game. It will be extremely helpful to know some things about music, but if you don't and are still interested in playing, some internet searches will prove useful.
The goal is to open the door into the Employees Only area in the back of my music studio. You will need twelve "keys," which, according to the Circle Of Fifths, is all of them. (Major keys, that is! See image in the upper right corner.)
In order to get each key, you will navigate a "task" scene in the studio. By clicking on areas and objects, figure out what needs to be accomplished and how to do it.
Once you are successful, you will need to find the hotspot to click on for an intermediate image. Then find the hotspot in the intermediate image to get to the treasure chest containing the key.
You will need to enter a passcode to open the chest. In order to be prompted for the passcode, you will click on the chest's hotspot. Clues to the passcode were provided in the scene you just left. (Sometimes there is no intermediate image; the clues were in the task scene.)
There are three categories of passcodes, viz.:
If you have any questions, well, you'll have to figure out the answers as you go along. Have fun!
NOTE: The layout probably looks best with screen resolution at 1152x864.