They were formed in 1971 when record producer Hans van Hemert brought together the solo talent of Mouth (born Willem Duyn, March 31, 1937) and Maggie MacNeal (born Sjoukje van't Spijker, May 5, 1950). Mouth had previously sung in a number of 1960s bands, including Speedway. MacNeal had released one solo single before teaming up with Mouth, a cover of Marvin Gaye's "I Heard It Through the Grapevine", also produced by van Hemert.
The duo released their first single, "Hey You Love", which reached #5 in the Dutch Top 40, while the next two singles "How Do You Do" and "Hello-A" both reached #1. In 1972, Mouth & MacNeal reached the top of the charts throughout Continental Europe and Scandinavia. "How Do You Do" was made popular in the United States by radio personality Jim Connors and the song eventually reached #8 in the U.S. in July 1972. "How Do You Do" spent 19 weeks in the Billboard Hot 100 and won the R.I.A.A. gold disc on 2 August 1972. Selling over a million copies in the U.S. alone, global sales exceeded two million.
This propelled their 1972 album How Do You Do into the Billboard 200 (US #77). More hit singles followed in 1973, and in 1974 Mouth & MacNeal represented the Netherlands in the Eurovision Song Contest placing third, behind ABBA and Gigliola Cinquetti with their song "I See a Star", which went on to be a #1 hit in Ireland.
In December 1974, shortly after their success with "I See a Star", Mouth and MacNeal split up. Mouth and his wife Ingrid Kup continued and formed the act Big Mouth & Little Eve, whereas MacNeal went back to solo performing. MacNeal went on to represent the Netherlands again at the Eurovision Song Contest 1980 held in The Hague, singing "Amsterdam", finishing fifth in a field of nineteen.
All of the above was found on Wiki's Fantastic site [here]
(My personal favorite)
Maggie in her own fashion desired to be known as a more traditional singer and she had the voice for it. I think she is one example of a performer being role classed based more on personal image than by the desire for the arts. This next cut is her on her own singing in her own style "Amsterdam". I think it's beautiful and wish I had had the opertunity to hear more of her own work done in her own style.
Please Rest in Peace and Lord be with you Mister Willem Duyn