Seven was the first Seger album to feature 'The Silver Bullet Band', which he would steadily rely on for the rest of his career. The album gained notorious recognition and is a fan favorite despite its rarity. The very successful tour for this album was kicked off with Seger and his newly formed Silver Bullets as the opening act for Kiss. Kiss asked Seger and the band to support them for a few shows. After seeing the band's first set, they offered Seger the rest of the tour, which gained the band much-needed recognition.
Early vinyl copies of the album featured the word 'contrasts' at the bottom of the cover, leading people to believe the album had two titles. Others believed the album was titled 'Seven Contrasts'. However, Contrasts is the name of the artwork featured on the album. The word in parenthesis is simply a reference to the artwork rather than an actual subtitle or title of the record.
A later bootleg of the album released in the 1980s was entitled Seven Worlds.
Although the album failed to make the Billboard Top 200 albums chart, the single "Get Out of Denver" reached 80. Critics and longtime Seger fans tend to regard the album as a lost classic, much like its predecessor Back in '72. For example, Stephen Thomas Erlewine of AllMusic retrospectively gave the album 5/5 stars, calling it "one of [Seger's] strongest, hardest-hitting rock records".
Summing up, Erlewine wrote:
Only nine songs, lasting just over a half-hour, but it's one of the most infectious sets Seger ever cut, proving that he wasn't just a dynamite rocker, but he had the songs to match. And, again, it didn't have any success – it didn't even chart, actually. That doesn't change the fact that this is one of his very best albums.
(en.wikipedia.org/wiki/Seven_(Bob_Seger_album))