I don't know much about Ballyhoo! and had trouble finding information on them. From listening to their other tunes their music appears to be a mix of Reggae and a little Pop with some Rock influences. One of their other available tunes 'Cali Girl' is more Reggae-like while 'Paper Dolls' is more of a Pop Rock style. As a side note, I found a song called 'The Struggle' by them which would be a good song choice for this game I think.
Paper Dolls opens with a simple power chord riff which reminds me of another popular song from about 10 years ago however for the life of me I can't pick out what that song is. It continues this riff until the lyrics are introduced and the song adopts more of a Reggae feel. I like how the guitar and bass play off each other in this one. I guess this is more a result of the Reggae genre where the bass handles more of the melody.
The chorus is very catchy and the guitar part just repeats through the same chord progression introduced at the beginning of the song. The song is fairly simple and follows a standard verse-chorus-verse-chorus-bridge-chorus type structure. The bridge is full of more chord changes like the chorus.
I really enjoy the song itself and am surprised it is does not have mainstream popularity as it sounds similar to many other popular tunes. I feel that this song is a hidden gem that the average DLC purchaser would probably enjoy. It's also nice to have more Reggae influenced music in Rock Band. If you like music from Bedouin Soundclash I would highly recommend you check out this band.
In the end, while the chart is not terrible exciting, I find this song a pleasure to play along to so it's guitar rating gets a little boost.