Ah, the dusty relic of analog dreams! First, strip the cassette deck so you can see the audio output jack—usually a 3.5mm stereo plug. Hook that up to a tiny microcontroller board like an Arduino Nano, but via a simple line‑level attenuator because the deck can be loud. Then add a small 8‑bit sound chip, like the SN76489, to generate glitchy synth bits and let the microcontroller feed it a random sequence. Use a MOSFET to drive a small speaker for the lullabies, but add a cheap piezo for those “time‑travel” buzzing vibes. Finally, program a tiny LCD to show a countdown of “seconds until next lullaby” and use a real‑time clock module for that sci‑fi touch. Keep all wires neatly bundled with colored heat‑shrink tubes, and make a spreadsheet that logs each glitch pattern, how long it lasts, and your mood when it triggered. Good luck, and may your glitchy lullabies never forget their own memory!