http://en.wikipedia.org/wiki/The_Singing_SenatorsMembers
Representation at 2000:
John Ashcroft (R-Missouri) - Baritone (lost re-election, became Attorney General, then retired)
Larry Craig (R-Idaho) - Lead
James Jeffords (R-Vermont) - Tenor (became an Independent in 2001) (Retired in 2006)
Trent Lott (R-Mississippi) - Bass
History
Beginnings
In 1995, at New Hampshire Senator Bob Smith's birthday party, Ashcroft, Jeffords, Lott, and Connie Mack of Florida sang "Happy Birthday". Later, when Senator Bob Packwood of Oregon was having a birthday party, Jeffords called Lott and suggested that the four of them sing at the party. Mack declined, but Larry Craig joined. According to his autobiography, Herding Cats, A Life in Politics, Lott formed the group in large part to improve relations between the Republican Conference, of which Lott was Majority Leader, and Jeffords, a Republican who frequently voted with the Democrats.
During the initial years, the four Senators usually practiced in Lott's hideaway office. Guy Hovis, the Mississippi state director for Lott, was a talented musician who gave the Senators some training.