When I first watched The Orville, one of the first things that stood out to me was the music.  It was highly inspiring and exciting, and very similar to some of the scores from earlier episodes of Star Trek: The Next Generation.  The Main Title of the show has an adventurous theme which appropriately depicts the mission of the Union.

Basically a shortened version of the Main Titles, is has some subtle differences but is always fun to hear after watching an episode of the show.  Bruce Broughton's score is definitely fun to play on the piano.  

The Orville: New Horizons is the rebranded name of The Orville's third season.  The show switched to a different network on TV and the tone shifted somewhat to become more serious.  Along with that came a change to the Main Title of the show, in which Bruce Broughton kept his theme but made a more dramatic, orchestral version.  

The End Titles of The Orville: New Horizons, like the End Titles from previous seasons, is a shortened version of the Main Title.  However, it brings back a little more of the adventurous, exciting rendition of the score from the previous seasons.