The earliest type of instrument is thought to be flutes. According to wikipedia this technology could be as old as 43,400 and 67,000 years. Simple devices for making rhythm where probably made: drums, rattles. But since they are usually composed of organic matter, they would decompose leaving little trace. Without knowing much I would guess that humans developed stringed instruments relatively early. My unscientific guess is that these kinds of instruments developed alongside bow and arrow. Making them perhaps 18,000 years old. Maybe even older. Or perhaps the use of instruments as a musical tool is more recent (maybe 9,000 years old). I’m very much colored by my perception of human artistic expression.<h4>
As technology advanced, so would the potential for musical instruments advance. With metal working cymbals, sistrum, bells as well as gongs can be made. Trumpets could be made in metal to produce new sounds.
Hydraulic and pneumatic
The use of a mechanical power source enabled the hydraulic organ. The church organs must have been expensive technological marvel. It is a huge and impressive instrument. Probably one of the must awesome noisemakers before the invention of electric instruments.
Ca 18th century
The invention of the piano is around the late 17th and the beginning of 18th century. It's an amazing technological advancement: A key operated string instrument.
The 19th century
One specific piece of technology are behind some of the brass instruments: Valves. A recent tech, developed in the 19th century. An older technique was to use keys to open holes in a wind instrument.
Early 20th century
In the 20th century electric instruments where developed. An excellent example of this is the electric guitar. The solid body electric guitar embodies the advent of modern industry. Produced with a wooden solid body and a bolt on neck together with magnetic pickup. It's industrial design! A continuation of the old stringed instruments into the modern era.
An exciting development is the theremin. An instrument totally unlike older instruments. Two metal antenna to sense the position of the hands to control frequency and amplitude.
We have the telharmonium from just before the 20th century. It's a musical instrument made with tone wheels
. It is an instrument that was made to generate musical sound from an electric signal. The instrument never caught on since it required immense amounts of power and weighed almost 200 tons. It was an impressive technological achievement since it could reproduce the sound of common woodwind instruments. Hammond created an affordable instrument, using tone wheels, called the Hammond organ.
With digitally generated sound, there are huge possibilities. There are enormous possibilities for advancing the usability of tone/sound generation. Another important factor is the price of instruments. A simple flute is very cheap. More complex instruments like an electric guitar or a keyboard are very affordable instruments. A keyboard has excellent usability: The keys maps to the chromatic scale.