Saturday's six groups include an a cappella group from Kings College London All The King’s Men, a Polish jazz group Alle Choir, the London International Gospel Choir, a female vocal soul group Songbird Sessions, a Welsh choir Sgarmes, and the newly formed 4 Tune Tellers and Kimmy.
To progress the groups must impress the panel of musical judges - the nation’s favourite choirmaster Gareth Malone, former choirgirl turned international recording artist Kelis and this week’s superstar guest judge singer songwriter Bebe Rexha.
The programme opens with an epic musical mash-up. Groups then go head-to-head in a series of knock-out choral challenges. First they will each perform their showstopper before battling it out with their opponent in a themed riff-off.
The judges will then decide which group goes through to the Solo Battles later on.
At the end of the programme only two groups will remain where they must face the ultimate sing-off - the Final Battle.
Here they share the same song, before superstar guest judge Bebe Rexha joins in with the group the judges have chosen to go through to the Final and one step closer to the £50,000 cash prize.
Pitch Battle, Saturday, 7.30pm, BBC One