Log on to an Internet search engine such as http://www.google.com, http://www.yahoo.com or http://www.bing.com. Type in phrases such as "melody search,'' "finding melodies'' and "finding songs by melody.'' Check the website services that come up to see how they want you to input the melody of the song.
Hum or sing the melody into a microphone connected to your computer.
Tap the rhythm of the song on the keyboard of your computer.
Type in the melody on a virtual piano keyboard. A virtual piano keyboard is an online tool that allows you to play a song by clicking on various keys.
Hum (or record) a song into your mobile phone. Phone in the recording of your song to a service that identifies songs.
Go to a karaoke bar and hum (or sing) the song to the audience. Somebody might recognize it.