Hi-Fi is a single card bingo with super cards, select-a-spot, advancing odds, extra balls, and the 'Bump' feature (only used on this machine).
The artwork is music-themed and gorgeous.
Backglass:
http://bingo.cdyn.com/machines/bally/hi_fi/dade.html
Cabinet:
http://bingo.cdyn.com/machines/bally/hi_fi/resources/cab-hi_fi-1.jpg
Playfield:
http://bingo.cdyn.com/machines/bally/hi_fi/resources/pf-hi_fi-1.jpg