All three instruments on this page are typical members of the orchestra's percussion section, but many people don't realise that they come from the Middle East. For hundreds of years Turkey ruled most of what we now call the Middle East and the Turkish bands that spread all over the region and into Europe usually included the triangle, cymbals and bass drum.
About 200 years ago Turkish style music became very fashionable in Europe and so Mozart, Haydn and Beethoven all used triangles in their orchestras to imitate the sound of the popular Turkish bands. Today the triangle is a permanent part of the percussion section and sometimes has very difficult music written for it. Although it seems easy to play, like most percussion it looks easy when it is done well, but when done badly it can completely ruin the music.
The cymbals have been used in music for thousands of years and many cultures around the world have used cymbals. TOrchestral clash cymbals originate from the Turkish Janissary bands. They carried pairs of thin matching cymbals that they clashed together as they marched.
The cymbals used in the orchestra can be very large and heavy in order to make a rich clashing sound. Unfortunately this can make them difficult to control, especially when the player has to clash them many times in quick succession such as at the end of Rossini's William Tell Overture.
The other thing that makes cymbals difficult to play well is that bringing them together squashes the air inside. As you try to press the cymbals together the air gets squeesed out all round the edges and all that rushing air under pressure can slow your arms down. This makes it much more difficult to bring the cymbals together at the right time.
If you watch cymbals players they usually clash in a scissor motion, glancing the cymbals off each other in order to avoid the air-lock problem.
The bass drum is a large wooden hoop which traditionally had an animal skin stretched across to make the drum 'head'. Modern bass drums use plastic instead of skins but musicians still call the hitting surface a skin. The bass drums used in the bands of the Ottoman Empire were built in much the same way as the modern bass drum.