Which symbol denotes the common time signature?

The symbol that denotes the common time signature is 4/4. This time signature indicates that there are four beats in each measure, and each quarter note receives one beat. It is one of the most widely used time signatures in Western music and serves as a foundational concept in rhythm and meter for both performers and composers alike.

A time signature like 4/4 provides crucial information for interpreting the rhythm of a piece of music, helping musicians understand how to count and group the notes. Musicians recognize 4/4 as "common time," making it a standard reference point when discussing rhythmic structure.

The other symbols listed serve different purposes in music notation. A fermata indicates that a note or rest is to be held longer than its standard duration, a repeat sign signals that a section of music should be played again, and a double bar line indicates the end of a section or piece of music. While these symbols are important in their own right, none of them convey the specific rhythmic framework that 4/4 does.