For all that I'm liable to complain about the system of labelling musical performers by genres, I find that I end up doing the same thing in my own way. It's only natural, I guess, to categorize music in some fashion — how else are you going to differentiate one piece of music from another? However, that's still a personal choice based on my own likes and dislikes and an understanding of the type of music I like to listen to when I'm in a certain frame of mind, not something that I'm going to use in order to answer the question: what kind of music do they play?
While it's true there are some musicians you can say play blues or rock fairly easily, there are other bands who just aren't going to fit into anybody's neat little categories no matter what you do. In fact, I'm discovering the music I'm enjoying most these days is that by performers who can't be pinned down as belonging to any single category. In some cases the number of genres they fall into is so great that they'd have more backslashes in any attempt to label them than the average website has in its address: they play a punk/jazz/folk/acoustic/blues/country/gypsy/swing sort of thing with some classical influences. By the time you get finished reciting a list like that it becomes meaningless and you might just as well have said they play music.
One of the most recent examples of this I've come across are the band Caravan Of Thieves. After having listened to their latest release, Bouquet, I could no more give you a one word answer to "what kind of music do they play" than I could explain higher physics equations. Even telling you that the four core musicians play guitar (Fuzz and Carrie Sangiovanni), violin (Ben Dean), double bass (Brian Anderson), and are occasionally joined by Bruce Martin on accordion, isn't going to help, as a lineup like that could indicate anything from a country group to a folk ensemble from the streets of Paris.
So what can I tell you about their music if I can't tell you what it is? I can tell you that lyrically they are sly and witty and musically they are full of life and vigour. I can also tell you that the singing of the Sangiovannis is perfect for the music as they harmonize beautifully without trying anything overly fancy, and have voices equal to the task of expressing the ideas, emotions, and humour in their songs. They are sufficiently skilled at playing their instruments to play fast enough to make your head spin and be equally effective playing something more pensive. Their music hops, skips, jumps, and swings through the twelve songs on the disc without once missing a beat or striking a discordant moment.