Animating them at the same time (other than Expressions).
- Adjustment Layers
- Parenting
- Pre-compose
Animation > Add Expressions Alt+Shift+=
Expressions (Default spatial interpolation > linear)
Affect individual parameters (Scale / Position / Rotation) to another parameters.
Option / Alt + Click stop watch

Drag & Connect to make the parameters on each object change simultaneously (can also link to different values or go into the codes (x, y) and link to values).

Coding Example
temp = thisComp.layer("Medium Magenta Solid 1").transform.scale[0];
[temp, temp] <-Original temp = thisComp.layer("Medium Magenta Solid 1").transform.scale[0]; [temp, temp+50] <-Change the y value

Simultaneously rotate etc.

The expression value does not have to be the same (IE: Link color to rotation so the color changes according to the rotation).
Effects > Expression control > Slider control
for more controls
Animation > Keyframe assistant > Convert Audio to Keyframes (to change audio to get the values).
Make sure to use .wav file.
2 more weeks to work on final.