Michael B Tretow, the celebrated sound engineer known for his work with ABBA, passed away last year. A commemorative plaque was unveiled in his honor on Friday afternoon. The plaque is located at Kungsgatan 21 in Norrköping, Sweden. Tretow’s contribution to ABBA's iconic sound was deeply significant, making him a legend in the music industry. The unveiling serves as a lasting tribute to his skill and dedication. The event was attended by fans and colleagues who wished to celebrate his life and legacy. This memorial recognizes Tretow’s lasting impact on popular music.