There are (at least) 3 bands by that name. The first one existed from 1975 to 1977 Widowmaker were a British hard rock group, who were active from 1975 to 1977. They were considered by many to be a supergroup and released two albums. Although their influences appeared to offer vast creative possibilities, musical and personality differences lead to their break-up. The legacy of Widowmaker is captured on the compilation Straight Faced Fighters (2002) released by Castle, which contains tracks from both of their albums. The band was formed by former Mott the Hoople and Spooky Tooth guitarist Luther Grosvenor,...
These are photos from concerts where Widowmaker played, so they may be of other bands that played the concert as well.
Reading Festival Aug 26 - 28, 1977 Reading, England, United Kingdom Uploaded by Mr.Bassman
The Dictators / Ramones / The Nuns / Widowmaker Jul 30, 1977 San Francisco, California, United States Uploaded by Zimtrim
Nelson Ledges Freedom Festival Sep 6, 1976 Warren, Ohio, United States Uploaded by Shulesjo2
Electric Light Orchestra (ELO) / Widowmaker Sep 3, 1976 Montréal, Québec, Canada Uploaded by Zimtrim
Electric Light Orchestra (ELO) / Widowmaker Sep 2, 1976 Tarrytown, New York, United States Uploaded by Zimtrim
Electric Light Orchestra / Widowmaker Aug 31, 1976 Normal, Illinois, United States Uploaded by Zimtrim
Electric Light Orchestra (ELO) / Widowmaker Aug 29, 1976 Chicago, Illinois, United States Uploaded by Cb 57
The Who / The Sensational Alex Harvey Band / Streetwalkers / Little Feat / The Outlaws / Widowmaker Jun 5, 1976 Glasgow, Scotland, United Kingdom Uploaded by Prc56