The Rocketeer is considered by many people to be one of Horner's best works, and you know, they might be right. The album opens with a peacefull pianosolo, with synths in the background, introducing the main theme. Then the whole orchestra takes over the theme and develops it. This music is perfect for the movie. It really feels like you're flying.
The second track is very good, very stirring (it sort of bounces along), action music. I like melodic action music, and this really is. In the third track Jenny's theme is heard for the first time. It opens with a romantic horn, one of Horner's trademarks. The theme is then played by the orchestra in all its grandeur. This track, and theme, is really great. "Neville Sinclair's House" is quiet music, that gives a feeling of night, but also of tension (it's been a while since I saw the movie, so I don't remember when it's used in the movie).
The final track starts almost exactly like the first. The rest of the track is a "medley" of the two themes, giving a great ending to a great score. It's worth noting the way Horner uses the main theme in the music. He makes it sound stirring, swell, heroic, relaxing and peacefull.