Editing The Guess Who (section)

=== Breakthrough and Classic Lineup (1965–1975) ===

Following Chad Allan's departure, [[Burton Cummings]] joined the band in 1966 as lead vocalist and keyboardist. The Cummings–Bachman songwriting partnership proved extraordinarily fruitful. After years of moderate success and relentless touring, the band broke through to international stardom in 1969 with the release of ''"These Eyes"'', which became a major hit across North America.

A string of chart-topping singles followed in rapid succession:

* '''1969''': "These Eyes", "Laughing", "Undun"
* '''1970''': "American Woman", "No Time", "Hand Me Down World"
* '''1971''': "Share the Land", "Albert Flasher", "Rain Dance"

''"American Woman"'' became the band's signature song and their only U.S. number-one hit, topping the [[Billboard Hot 100]] in 1970. It was also notably the first single by a Canadian rock band to reach number one in the United States.

Randy Bachman departed in 1970 to pursue a solo career and later found success with [[Bachman–Turner Overdrive]]. Despite the loss, Cummings carried the band forward with new guitarists Kurt Winter and Greg Leskiw, and later Domenic Troiano.