What does it mean when some notes have arcs connecting them to other notes?

Question:

What does it mean when some notes have arcs connecting them to other notes?

I'm assuming it means to hold that note until you reach the other note it is connected to, but isn't that assumed? I mean, if an arc connects a half-note C to a half-note C, then a half note G is shown (all in one 4/4 measure), isn't it assumed you were going to hold that C for a halfnote anyway? What's the point of that arc?

Best Answer - Chosen by Asker: The symbol is called a tie when it is between two notes of the same pitch within a measure, and a bridge when between two notes of the same pitch crossing from one measure into the next.

When it is between two notes of different pitches, or crossing over several notes of varying pitch, then it is called a slur, and that means that all of the notes are played without stopping, as in a bend, or a legato (slide), as opposed to playing each individual note in rapid succession.

In drum music, you will often find a number written within the arc (an 8 for example) and that tells you the duration of the notes encompassed by the arc. In other words, if there are 5 notes covered by an arc with an 8 in it, then all five notes would occupy the space of an eighth note.