The most convenient way to use the computer as a musical instrument, connecting it to a MIDI-keyboard.
But if it does not, you can play on your keyboard designed for typing.
Install on your computer program,allows you to use normal keyboard as a musical. Which one depends on the operating system installed on the machine. For Windows suited, for example, PC 73 Virtual Piano Keyboard, KeyMusic. The first of them allows you to play both the physical and the virtual keyboard, the second - only the physical, but has a more interesting opportunity: working in the background, and the notes sound even when you type characters into any other program. There is Analogx Vpiano program, but it only works with a sound card that has hardware MIDI-synthesizer or its emulator.
In Linux, you can run any of the aboveprograms with Wine emulator. If you do not like it, use the application of similar purpose, designed specifically for Linux, for example, or Vkeybd Jack Keyboard. Both, like Analogx Vpiano, require a sound card with hardware MIDI-synthesizer or synthesizer emulator such (for example, Timidity).
To play on a virtual piano directly inbrowser, go to the website or to the site TheVirtualPiano Virtual Piano Keyboard Online. Applications are made in Flash and are compatible with all platforms where Flash Player Get there, including Linux, Windows and Mac OS X. They allow you to play chords, causing each of them a digital key.
No matter what kind of program you have selected,refer to its online Help with matching keys computer keyboard notes. No standard is not here. If the software allows you to reassign keys, if you wish use this function, you choose a convenient location of notes on the keyboard.