As the album's title suggests, this was originally recorded in 1986. It was originally intended for a second album by Hackett's short-lived supergroup GTR, which never materialized.
Chris Thompson of Manfred Mann's Earth Band sings lead on this, and Queen's Brian May joins Hackett on co-lead guitar.
This song's intro is set during an effete, high-class ball. It opens with an orchestral waltz and a man asking, "Would the lady care to dance?" Once the lady says yes, the waltz is replaced with a brief, rapid-fire guitar solo by Hackett, which leads into the song itself. XM Satellite Radio has been known to use this intro in some of its channel-ID audio bites.
The song itself is a straightforward ode to the ever-popular gambling device, often called the "one-armed bandit." Hackett had the old-fashioned mechanical reel variety in mind, as the more sophisticated (and often armless) video-based slot machines now prevalent in today's casinos hadn't yet been invented in 1986.
The "number [Hackett's] dreaming of" in the second verse is presumably the number 7. Not only is this a commonly-used symbol on slot machines, but a row of all sevens is often designated the jackpot-winning combination.
In the final verse, Hackett (via singer MacDonald) warns listeners not to play a slot machine for too long, lest they lose everything. Like most other casino games, slot machines give a slight built-in advantage to the house over the player, by providing payouts that don't quite reflect the true odds of winning. So, if you play a slot machine long enough, you will eventually lose all the money you started with; it's just a question of how long it takes.
As the song ends, we're returned to the ballroom setting from the intro, where the lady discovers that she's torn her dress, presumably while dancing to this high-energy song.
Joshua - La Crosse, WI, for all above