The episode saw Mark De-Lisser visit Monmouthshire in Wales to create a choir made up of people from rural areas.
While at Kent, Ella sung in a rock band. The programme features Ella and others from Welsh communities form a choir to put on a life-changing performance.
The finale will be broadcast at 9.15 on Friday 20 December 2019.
Ella first features 8 minutes into episode 1 of the series, which is available on BBC iPlayer for a month:
UPDATE: You can see Ella singing in the final episode of the series here: