I don't get how people are saying Katy tho, or Rihanna
Katy:
Katy Hudson --- Gosepl, Contemporary Christian Music (flopped)
One of the Boys --- Pop rock, soft rock, indie rock (1 #1, 2 top tens)
Teenage Dream --- Pop, rock, dance (6 #1's, 2 top 10's, one of the biggest eras in music history)
Rihanna:
Music of the Sun --- Dancehall, reggae, R&B (1 top 10)
A Girl Like Me --- Dancehall, dance-pop, R&B (1 #1, 2 top 10's)
Good Girl Gone Bad --- Dance-pop, R&B (3 #1's, 2 top 10's, one of the biggest eras in music history)
Rated R --- R&B, dubstep, rock (1 #1, 2 top 10's)
LOUD --- Pop, dance-pop (3 #1's, 1 top 10)
Talk That Talk --- Pop, dance-pop, electronic (#1, 1 top 10)
Both of them constantly get bigger and bigger as their sound evolves