Is this a trombone or a marimba?
There are thousands of instruments in the world. Even though it would be a career in and of itself to know all of them, I try to learn and teach as many of them as I can. Being able to tell the difference between a cello and a violin or a trumpet and a tuba has to do with timbre. Timbre is the character or quality of a musical sound, or voice, as distinct from its pitch and intensity. Here is a simple way that I work on this with a group of dance students:
Use a white board/chalk board to make a list of every instrument that the group of students can think of. Each time a student names an instrument, ask them to give a short description of it and how they know of it. Include the name of every instrument, even if they do not know exactly what it is, but have heard of it. Use the list below as a reference to see if any have not been named.
Depending on the amount of students in the class, ask each student to pick an instrument that they have not heard of before. Have each of the students do some research on the instrument and find a YouTube video of an example of someone playing that instrument. Find a time or place to share each of the new instruments to the class. If you have a shared online space that students can post text and video, this works really well. I have also used the first 10 minutes of a class, throughout a semester, to have each student speak a bit about the instrument and show some of the video examples. This is a fun and engaging way to have the students become the teachers in the classroom. It encourages using musical language to describe and then demonstrate the magic of each instrument's abilities and timbre.
Another variation on this exercise is to have each student create a short solo to a solo performance of that instrument.
Instrument List:
Keyboards - Piano, Celesta, Rhodes, Organ, Synthesizer, Toy Piano, Wurlitzer, Harpsichord
Percussion - Timpani, Bass Drum, Snare Drum, Wood Blocks, Marimba, Vibraphone, Xylophone, Glockenspiel, Hand Bells, Jingle Bells, Cowbell, Wind Chimes, Tibetan Singing Bowls, Triangle, Steel Drums/Pans, Kick Drum, Snare Drum, Toms, High Hat, Cymbals, Drum Machine, Hand Percussion, Tabla, Congas, Bongos, Tambourine, Cajon, Frame Drum, Djembe, Riq, Timbales, Dumbek, Maracas, Rain Stick, Finger Cymbals, Castanets.
Brass - Tuba, Flugelhorn, Trombone, Euphonium, Trumpet, Cornet, Bugle, Pocket Trumpet, French Horn, Alphorn or Alpine Horn
Strings - Double Bass, Cello, Viola, Violin, Guitar, Banjo, Lap Steel, Koto, Harp, Mandolin, Bazooki, Oud, Sitar, Ukulele
Wind/Reed - Piccolo, Flute, Bass Clarinet, Clarinet, Oboe, Bassoon, Soprano Saxophone, Alto Saxophone, Tenor Saxophone, Baritone Saxophone, Kazoo, Recorder, Pump Organ, Accordion, Bagpipes, Harmonica, English Horn
Voice - Vocoder, AutoTune
Electronic Instruments - Theremin, Computer, Modular Synth, Sampler, Drum Machine, Tape Recorder, Turntable