Some notes can be played with different valve combinations on trumpet. For example, the E on the 4th space can be played 4 different ways, making it one of the most expressive notes on the horn (the fingerings are: open, 3rd valve, 1st and 2nd valve, and all 3 valves). It's a handy skill. "Sound the Trumpet" (link above) contains a fingering chart with alternate fingerings.
In this video, learn the techniques necessary to get the most out of this important trumpet skill.
Jonathan Harnum is a musician, author, and teacher with a PhD in music education from Northwestern University. He's the author of several music books, including "Sound the Trumpet: How to Blow Your Own Horn," "Basic Music Theory: How to Read, Write, and Understand Written Music," and "The Practice of Practice."