What genre do songs that dont have any accompanying music belong?

Personally, I’d argue that there’s no particular genre for such songs. They could be pop, folk, jazz or slam poetry, depending on their actual, um… genre.

If you must group them all together, however, I’d label them A cappella.

plainsong or vocal music

lack of accompaniment doesn’t make it a particular genre—give us examples of the kinds of songs you mean and perhaps we can help with the correct terminology

a capella for unaccompanied choral music.

Sorry- misspelled and repeated..rushing bad!

Unaccompanied songs can be called “a capella”, but I wouldn’t say that is a genre, but rather a simple descriptor. A capella songs may be common in a particular genre such as the spiritual genre which derives from American slavery, but can occur in other genres as well.