In Kpop, most groups describe their members with roles like the following

Leader
Main/Lead vocal
Main/Lead dancer
Visual
Maknae (youngest, a default title)
Spokesperson (most charismatic/talktative in interviews)

What would you give western groups if asked for these?

Little Mix:
Leader: Jesy
Main vocal: Perrie/Jade
Main dancer: Leigh-Anne
Visual: Leigh-Anne/Jade
Maknae: Perrie
Spokesperson: Leigh-Anne/Jesy


One Direction:
Leader: Harry
Main vocal: Harry
Main dancer: ??
Visual: Zayn
Maknae: Harry
Spokesperson: no clue

Fifth Harmony (haven't kept up with them seriously since X-factor):
Leader: Lauren
Main Vocal: Lauren
Main dancer: Normani
Visual: Normani
Maknae: Dinah-Jane


PCD
Leader: Nicole
Main vocal: Nicole
Main dancer: Kimberly
Visual: Nicole
Maknae: Melody
Spokesperson: Nicole


Destiny's Child
Leader: Beyonce
Main vocal: Beyonce
Main dancer: Beyonce
Visual: Beyonce
Maknae: Beyonce
Spokesperson: Beyonce


N*Sync:
Leader: Justin
Main vocal: Justin/JC
Main dancer: Justin/JC
Visual: Justin
Maknae: Justin
Spokesperson: ?? (probably Justin)


Those were just a few I could think of. Maybe someone could do Girls Aloud, The Saturdays, 5SOS, etc?

Selena Gomez & The Scene

Selena - HyunA
The Scene - the rest of 4minute

The Saturdays
Leader: Una
Main vocal: Vanessa/Rochelle
Main dancer: Frankie
Visual: Mollie
Maknae: Vanessa
Spokesperson: Probably Rochelle

Take That
Leader: Gary
Main vocal: Gary
Main dancer: Howard/Jason
Visual: Gary/Mark
Maknae: Robbie
Spokesperson: Gary

G.R.L.
Leader: Lauren
Main vocal: Simone/Emmalyn/Natasha
Main dancer: Paula
Visual: Lauren
Maknae: Emmalyn
Spokesperson: Lauren