The most convenient way to use your computer as a musical instrument is to connect a MIDI keyboard to it. But if it is not there, you can play on a keyboard designed for typing.
Instructions
Step 1
Install a program on your computer that allows you to use a regular keyboard as a musical keyboard. Which one depends on the operating system installed on the machine. For Windows, for example, PC 73 Virtual Piano Keyboard, KeyMusic are suitable. The first of them allows you to play both on the physical and on the virtual keyboard, the second - only on the physical, but has a more interesting feature: it works in the background, and the notes sound even when you type symbols in any other program. There is also the Analogx Vpiano program, but it only works with a sound card that has a hardware MIDI synthesizer, or its emulator.
Step 2
On Linux, you can run any of the above programs through the Wine emulator. If that doesn't work for you, use a similar-purpose Linux-specific application such as Vkeybd or Jack Keyboard. Both, like Analogx Vpiano, require a sound card with a hardware MIDI synthesizer or an emulator of such a synthesizer (eg Timidity).
Step 3
To play the virtual piano directly in your browser, go to TheVirtualPiano or Virtual Piano Keyboard Online. The applications are made in Flash and are compatible with all platforms where Flash Player is available, including Linux, Windows and Mac OS X. They allow you to play chords by calling each of them with one number key.
Step 4
Regardless of which program you choose, see its help for mapping the keys on your computer keyboard to notes. There is no standard here. If the program allows you to remap the keys, if you want, use this function by choosing the location of the notes on the keyboard that is convenient for you.
