Sims who have the Music Lover trait will, while in Live Mode, occasionally do the same idle animation that plays when you click on the Music Lover trait in CAS.
Latest: V3, released after EA Patch, November 13, 2018
This mod is a simple animation change/addition. It takes the existing "Music Lover" trait idle animation that plays when you click on the trait in CAS and makes it so that if a Sim has the Music Lover trait, they will occasionally play the same animation in Live Mode.
The frequency is identical to the special idle animation that Dance Machine has. It is as follows:
Initial Time - Min: 240 (4 hours), Max: 480 (8 hours)
Normal Frequency after Initial - Min: 360 (6 hours), Max: 1440 (24 hours)
You may be wondering what the reason for this mod is or why it would make a difference. In my observations in playing The Sims 4, I've found that idle animations make a significant difference in making Sims feel unique, noted most starkly in Toddlers.
This mod was a simple and relatively easy-to-add concept to expand on the unique feel of Sims (in this case, Music Lover Sims) just a little bit.