Here is the 2nd Fluttershy lead for M6A Season 4; While My Guitar Gently Weeps Suggested by Infernite Ninja. 
I must admit, this was an odd choice for Fluttershy lyric-wise. Though it's the 2nd Beatles one with her on the lead.

AJ: You own a guitar Flutters?

Fluttershy: Um........Apparently?

Applejack - Alto 2 (Lowest part)
*Bass Line
Twilight Sparkle - Alto 1 (Second Lowest Part)
*Percussion
Rainbow Dash - Soprano 2 B (Third Lowest Part)
*Harmony 1
Pinkie Pie - Soprano 2 A (Third Highest Part)
*Harmony 2
Rarity - Soprano 1 B (Second Highest Part)
*Harmony 3
And Fluttershy - Soprano 1 A (Highest Part)
*Lead Vocals

#Mane6Acapella
#Fluttershy
#MuseScript