Cincinnati's batters were hot, "red hot" if you will, as the team outslugged the Cubs in Chicago, 12-7. In doing so, the Reds homered in six straight innings, the second through seventh; they added another in the ninth, as well.

Here at the Hot Hand page, we try to get an idea of how unlikely something is, through either a statistical or historical lens. In this instance, an historical reference point is readily available. According to this MLB.com article:

More breathing room came as [catcher David] Ross led off the seventh with his second homer of the game -- this time a shot to left field. It gave the Reds a home run in six straight innings, marking the first time they'd done so since Sept. 4, 1999, when they slugged homers over seven consecutive innings at Philadelphia.

OK, so we have an answer. For the Reds, at least, nearly nine years had elapsed since the last time this happened.

This ESPN.com article has an accompanying chart of all the scoring plays in the Reds-Cubs game.

This Baseball Almanac page lists a number of different kinds of home-run records, including each franchise's record for most homers in a single game. Several teams have hit eight (or more) homers in a game. Visual inspection of box scores would be needed, of course, to see over how many consecutive innings a team's homers were hit, in a particular game. The more homers hit within a single inning, the fewer innings would be needed to accumulate a bunch of dingers.