Examples of resonance of sound in tubes

[Soph90]

Hello :)
We did a lab in class and the lab was about resonance of air columns. We used a tube and filled it with water. Then we held a tuning fork above the tube to see at which points the resonance occurs. If a vibrating fork is held over the open end of the column, the loudness of the sound will increase very sharply at specific lengths of the tube. Now the problem is I have to come up with a real-life application of resonace of sound in tubes, and I can't seem to think of an example. Help me!

 

[Nick89]

You can't think of any example of applications of resonance in tubes? Just about any musical instrument that consists of mainly a tube (flute, trumpet, marimba (if it has these tubes hanging underneath) etc..) uses exactly this principle.
Also I believe amplifiers (for example a guitar amplifier) use tubes like this.

 

[Soph90]

Thanks

 

[xArcherx]

The organ is a classic example.