Question: What Canadian folk singer and songwriter performed with Jack Nissenson in The Mountain City Four?
Context: Ian Robb is an English-born folk singer, currently based in Ottawa, Ontario.  He was a founding member of Friends of Fiddler's Green, and a columnist for Sing Out! .  He is also a member of the Canadian folk trio Finest Kind.  He wrote a parody of Stan Rogers song "Barrett's Privateers", titled "Garnet's Homemade Beer".  He was the recipient of the 2005 Canadian Folk Music Award for Best Traditional Singer, for his work on the CD "jiig". The Mountain City Four were a Canadian folk music group, based in Montreal and active from 1963 (1963) –1967 (1967) .  The group consisted of Jack Nissenson, Peter Weldon, Kate McGarrigle and Anna McGarrigle.  They are primarily remembered for popularizing a number of songs by Wade Hemsworth, including the National Film Board animated short "The Log Driver's Waltz", as well as for Nissenson's recording of Bob Dylan's 1962 Finjan Club concert in Montreal. Albert Wade Hemsworth (23 October 1916 – 19 January 2002) was a Canadian folk singer and songwriter.  Although he was not a prolific composer, having written only about 20 songs during his entire career, several of his songs — most notably "The Wild Goose", "The Black Fly Song" and "The Log Driver's Waltz" — are among the most enduring classics in the history of Canadian folk music. Ian Bell (born 1954) is a Canadian folk musician, composer, and singer-songwriter who has been active in the Canadian folk music scene since the 1970s.  With Anne Lederman, he was part of the seminal Canadian folk group Muddy York.  He has been the leader of The Dawnbreakers and Professor Chalaupka's Celebrated Singing School.  Bell has performed at the Edmonton Folk Music Festival and the Mariposa Folk Festival, among others.  He has contributed to the development and preservation of Canadian folk music for more than twenty-five years.  He sings both old songs and his own original compositions.  His music has a Celtic flavour.  He is a versatile musician who plays several instruments. Bob Bossin (born 1946) is a Canadian folk singer, writer and activist who co-founded the Canadian folk group Stringband with Marie-Lynn Hammond.  Bossin is the writer of the songs "Dief Will Be the Chief Again", "Show Us the Length", "Tugboats", "The Maple Leaf Dog" and "Sulphur Passage (No pasaran)".  As well, Bossin wrote and performed two solo musicals, "Bossin's Home Remedy for Nuclear War" and "Davy the Punk".  The latter is based on the book "Davy the Punk" (The Porcupine's Quill, 2014), Bossin's memoir of his outlaw father. State Route 225 (SR 225) is a state highway in Elko County, Nevada, United States.  Known as the Mountain City Highway, it connects the city of Elko to the town of Owyhee near the southwestern Idaho border via Mountain City.  The route provides connections to Mountain Home, Idaho and Interstate 84 via Idaho State Highway 51. Craig Cardiff (born 9 July 1976) is a Canadian folk singer from Waterloo, Ontario, who has released sixteen albums, both live and studio-based since 1997.  He regularly tours North America and Europe, and lives in Arnprior, Ontario.  In 2012, Cardiff was nominated for a Juno Award for Roots and Traditional Album of the Year: Solo and for a Canadian Folk Music Award as Contemporary Singer of the Year. Jack Nissenson (1933-June 24, 2015 in Montreal) was a member of the Mountain City Four, a Canadian folk music group, based in Montreal and active in the 1960s.  In addition to Nissenson, the group consisted of Peter Weldon, Kate McGarrigle and Anna McGarrigle. Anna McGarrigle, CM (born December 4, 1944) is a Canadian folk music singer and songwriter who wrote and performed as a duo with her sister, Kate McGarrigle, until Kate's death in 2010. Canadian folk music has a long history, dating from the 16th and 17th century, mostly derived from the music of early settlers; much earlier for the music of indigenous people.  Folk music thus differentiates between traditional and contemporary.  Many of Canada's most influential folk artists emerged in the contemporary folk music era, notably Bruce Cockburn, Buffy Sainte-Marie, Ferron, Gordon Lightfoot, Joni Mitchell, Kate & Anna McGarrigle, Leonard Cohen, Murray McLauchlan, Stan Rogers, Valdy, Penny Lang and Wade Hemsworth.  In the 1970s, chansonniers grew steadily less popular with the encroachment of popular rock bands and other artists, and many of the folk clubs, such as the Montreal Folk Workshop, and groups such as The Raftsmen, the Mountain City Four and, eventually, The Travellers, that had served to foster the mid-20th century revival closed down.  Some new performers did emerge, however, including Jacques Michel, Claude Dubois, and Robert Charlebois.  The Canadian Folk Music Awards are presented annually to musicians carrying on in the tradition.
Answer: Anna McGarrigle