Stop previuos song when new song is playing

Very difficult to answer this without a URL.

Some players like Vimeo will add a dnt parameter to the embed – which is set to 1 by default.
You can change the dnt to 0 and it should only play one piece of media at a time.

See the docs here :
https://vimeo.zendesk.com/hc/en-us/articles/360001494447-Using-Player-Parameters