Why do equivalent notes played on different instruments sound different?

Question

So if an A is 440hz, why does a piano playing an A sound different than a violin, a guitar, or someone’s voice making that same A 440 note? It’s obvious that the pitch is the same on each instrument but each instrument has a distinct sound. I’ve never heard an A on a piano and thought, is that a piano or a cello. Why can we distinguish between instruments?

In: 151

Answer 1

I heard trumpets that sounded similar to electric guitars at a Voo Doo Glow Skulls concert before.