also: シンセサイザ
noun
synthesizer
Refers to the electronic musical instrument that generates and modifies sounds.
彼は新しいシンセサイザーで曲を作っている。
He is making a song with his new synthesizer.
Standard katakana spelling for the electronic musical instrument.
Variant without the long vowel mark; less common but still seen.
キーボード is a broader term for keyboard instruments, including digital pianos and MIDI controllers, while シンセサイザー specifically refers to sound-synthesis instruments.
Borrowed from English 'synthesizer'.