What does “jammy” mean here?

Question

The Tedeschi Trucks Band is like a large-format guitar-centric orchestra of jammy, bluesy Southern rock and soul. (source)

The word "jammy" in the sentence doesn't make a lot of sense to me. The noun "jam" in the context of music refers to a song or a musical piece. By extension "jammy" possibly means "musical"? I can't imagine what a musical band would be. Any band non-musical? All the dictionaries I have checked give "jammy" as "lucky" or "covered in jam", neither of which fit in the context.

Artistic license? Misuse of word?

Answer 1

A jam has broad meaning, but it implies a certain style of music. Jamming usually means a band is playing live and boisterously, and there is often a spontaneous, improvisational element to the music. A jam is often a long song, during which various musicians might play extended solos. The emphasis of the music is on performance rather than on composition. A "jam band" is typically a rock band with guitars (though not always), and it often incorporates elements of jazz or blues or Latin music. Percussion is also an important aspect of jamming, as it's important to keep the beat going for long periods of time.

I don't think "jammy" is a real word in American English, although it appears to be a real word with different meaning in British English. "Jammy" in American English would commonly be understood to mean that the band has some of the characteristics of a jam band without being a "jam band," per se -- just as "bluesy" means it has some of the characteristics of a blues band without being strictly a blues band.

Answer 2

See Jam band. "Jammy" would be "with a style like a jam band".

Or possibly "having a jam-like consistency" .. but which should be obvious from context.