Tracey Ullman "They Don't Know" (1983) and as Dame Judi Dench (2008) ;

In the late 1980's I thought Tracey Ullman was about the most talented person on network television with her Tracey Ullman show which featured her doing at least three different characters on a half-hour comedy sketch show.

I was also pleasantly surprised to know she was the same Tracey Ullman who had recorded a cover of this song a few years back.
From Wikipedia:

In 1983, Tracey Ullman, before she became better known in the United States as a comedy actress,included a version on her debut album, You Broke My Heart in 17 Places. This song was the album's most successful single, charting in the top ten of various national charts. MacColl performed backing vocals on Ullman's version and reprised her original "bay-ay-be-ee" in the middle of the song, which went to #2 in the U.K., #8 on the Billboard Hot 100 and #11 on the Adult Contemporary chart in the United States, and became the theme song for the final three seasons of Ullman's later television series Tracey Takes On.

Twenty Five years later here she is on Showtime's "State of the Union"   as Judi Dench (contains adult content)