One way musicians create tension in a melody or chord progression is through use of a suspension.
Here’s a little music theory for you: the suspension. A suspension is a note that clashes with the harmony and needs to move to another note to resolve the tension. For instance, the fourth note above the root of a chord is dissonant, and likes to move to the third note, which is consonant. Here’s a 4-3 suspension on a piano; the tension in this C chord is resolved when the dissonant F moves to the consonant E:
Example 1: 4 3 suspension.piano