Google believes you don't have to be a virtuoso to make decent music as evident by their Chrome Music Lab initiative. If you're not aware, Chrome Music Lab is, in Google's own words, "a website that makes learning music more accessible through fun, hands-on experiments."
The latest of these experiments is Google's "Song Maker" tool which, as the name suggests, allows you to create your own unique melodies quickly and easily from within your mobile or desktop browser. To use Song Maker, simply visit the official experiment page and begin "painting" notes on the large grid provided by Google.
Users will be able to choose two separate instruments for their composition as well as set a specific tempo. The first group of instruments includes synth, marimba, piano, strings and woodwind while the second group is comprised of "conga," electronic, blocks and kit.
It doesn't look like you can paint individual notes with a specific instrument as your created song will always play the sounds of the two instruments you've selected.
For more music-savvy individuals, the settings menu includes a few more customization options such as length, beats per bar, the music's scale and even instrument octave range. Furthermore, if Google's provided array of instruments isn't quite enough for you, it's also possible to use your mic to add your own voice to tracks.
Once you're finished playing around, saving your work is simple - just hit the 'Save' button in the bottom right corner and Google will provide you with a shareable link. Unfortunately, it doesn't appear to be possible to actually save your composition as an audio file for direct download meaning Song Maker probably isn't the best solution for professional music production.