If you're as confused as I was when I read this name here's an oversimplified explanation of a simple exclamation: "Glossary" is the name of the band; you are not, in fact, reading a review of the book "Glossary". Furthermore, I like this band so I added an exclamation mark to their name to show my supportive enthusiasm.
"Glossary" recently released their album "Long Live all of Us"; it's a mix of pop and soft rock with soulful, positive lyrics.
