Staffs & Clefs
Music is written on a five line staff. It's predecessor, a 4 line staff (Neumes), is mistakenly attributed to Guido of Arezzo, but he did not invent any staffs. He invented a notation system to assist Gregorian singers. Since 500 BC, music has evolved and today it is still changing.

The clefs commonly in use today are the Treble Clef (G Clef) and the Bass Clef (F Clef). These clefs encircle around G and F as shown on the right. The mnemonics used to memorize the notes of these clefs is illustrated in the top diagram. At this point in time, we will dispense with the pitch references G4 and F3 respectively as most people do not refer to their respective octaves by saying that they are going to play "G4" or "F3" ... or "C4" (Middle C). Those who memorize the clef notes, should just use the letter associated with the note.
Treble Clef:

Bass Clef: