This is an Asus4 chord that sounds like an organ. It uses 26 oscillators with six different frequencies for the notes A, E and D.

This sound uses 29 oscillators at randomly selected frequencies.

This sound uses 3 sin oscillators at 466.163757Hz, 329.62753Hz and 233.12Hz to create a dial tone.

This sound uses 3 sin oscillators at 440Hz, 401Hz and 391.995 to recreate a phone ringing. There volume is controlled with a timer to achieve the ringing on/off.