There are many themes in
Rome's Revolution which are presented to form continuity throughout the series. One such theme is represented by Rei's music slab which is a solid state device, conceptually similar to an iPod. This device contained all of the music Rei ever loved burned into an integrated circuit which was embedded in a solid slab of silicon:

The outer section was a pure mono-crystalline concentrator triple-junction solar cell. It is nearly 50% efficient in converting light into electricity. The front panel also has a dimly lit LCD panel built in which is touch sensitive. The file system allows you to search by genre, album title, recording artist or by any of a number of other criteria. There is also a randomizer option.
Along the bottom edge is a powerful magnet and two inductive ports for attaching the earbuds. MINIMCOM was also able to rig a connector so that Rei could play his music for Rome during their year-long journey in the
Flying House.
Here is just a partial list of the times this music slab is mentioned:
- Intro to Part 2 of
Rome's Revolution.
- When Rei and Rome returned to the Ark II to look for the data slabs in
The Ark Lords.
- In
Rome's Evolution, Rei had to give up
his sunglasses to account for the extra weight of the music slab.
- Also in
Rome's Evolution, Rei recalled his space walk to acquire the music slab.
Tomorrow, I will give you the little scene where Rei received the music slab from his parents.