The Box of Sounds was built over 25 years ago by a then 12-year-old Russ. Function wise this device is basically perfect as a stand alone experimental noise maker and an Audio generator. You have Volume, Built-In speaker, oscillator pitch, LFO with Rate control, and an indicator, old style frequency range selectors, switch patching, and an On-Off switch. All for what appears to be $15 in parts plus a sound generator IC. Circuit wiring is nothing more than a direct implementation of the SN94281 Datasheet schematic, but the user interface and its functional simplicity is something note because it can applied to other basic oscillator circuits.
Here is a video demo.
Seen on Make:Blog