These are the two theme cues used by MLB on FOX during the starting lineup / defensive alignment intro segments. It was used from FOX's inaugural 1996 season through the 2006 season. FOX altered their theme cues in the 2007 season, and as far as my research goes, dropped the starting lineup theme during intro segments.

Then, as per Wikipedia: "Beginning at the 2010 National League Championship Series, the NFL on Fox theme became the official theme music for all Fox Sports broadcasts, regardless of sport. In particular, current Fox Sports president Eric Shanks believed that the special theme music it had previously used for post-season baseball was not upbeat enough, and that the change would "[give] all of our sports sort of that marquee feel and it gives us a more upbeat way to come on the air." The change also resulted in the removal of the long-time Major League Baseball on Fox theme (also composed by Schreer)."

In this video, I've taken screenshots of the on-screen graphics used during the intro segments and have ordered them in chronological order from 1996 through 2006. As a byproduct of that, you can see the change and evolution of FOX's on-screen graphics through the years.

One last note here, I do realize these themes were still being used in 2007, as the video title reads from 1996 thru 2006. FOX used these themes during only the first month or so of 2007, before they switched to the updated theme that was used from 2007 thru 2010, and the lineup themes weren’t being used anymore. I only surveyed the FOX graphics from the time these themes were being used during the 1996 thru 2006 World Series (and 1997, 1999 ALCS, as the World Series was aired on NBC those years). By the time the 2007 World Series happened, they had already switched to the updated MLB on FOX themes.

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