Listen to By Gentle Powers online. By Gentle Powers is a German language song and is sung by Siegfried Fietz. By Gentle Powers, from the album Space Sinfonie · Space Songs (Ein Flug zum Mond mit Apollo 15 Astronaut James B. Irwin), was released in the year 2011. The duration of the song is 6:35. Download German songs online from JioSaavn.