1974 - Antoni Krupa, after four years of playing with Jazz Band Ball, in yet another band - with Marek Grechuta. The band's name stands for W Innej Epoce Muzycznej - "In Another Musical Era" (and the word "wiem" itself means "I know"). The band featured well-known musicians who went on with their musical careers. The band was joined by the singer Marek Grechuta, one of the best known and most distinctive of later years.

 Line-up in 1974:

vocals - Marek Grechuta
guitar, vocals - Antoni Krupa
violin - Piotr Michera
drums - Kazimierz Jonkisz
bass - Jan Cichy
piano - Eugeniusz Obarski