Random songs while listening to a playlist/album

[Tv18]

When I start listening to a playlist I made, it plays a few songs from that playlist, and after that it starts playing complete different songs, which are not in the playlist and i have never heard of before. Is this because i have a free account? Does someone know gow to fix this?

[mariahchristyl]

You have to have a premium acoount to avoid this.