Gunder Hägg was the band's new name when they released their first LP in 1969. Their first public appearence as a band was at the Andy Warhol exhibition at Moderna Museet in Stockholm, Sweden in February 1968. They called themselves Tjalles Horizont on that occasion. During the rest of the spring in 1968, they toured using the band name Sound of Music. Torkel Rasmusson had written a vignette song called "Come to where the flavour is / come to Sound of Music", and accompanying the band was also Leif Nylén's wife, Elisabet Nylén, on cello on this mini-tour. In May 1968, Urban Yman and Kjell Westling joined the group, and soon thereafter Gunder Hägg was formed. After a dispute with the former Swedish world track and field record holder, Gunder Hägg, the band name had to be changed. So from 1972, they called themselves Blå Tåget.

Members in Gunder Hägg on all albums: Mats G. Bengtsson, Tore Berger, Leif Nylén, Torkel Rasmusson, Kjell Westling and Urban Yman.
Member in Gunder Hägg on Tigerkaka in1969: Göran von Matérn; Member in Gunder Hägg on Vargatider in 1970, and on Glassfabriken in 1971: Carl-Johan De Geer.
Appearing on different tracks with Gunder Hägg on Tigerkaka, Vargatider and Glassfabriken: Roland Keijser.