Place your right thumb on middle C. Middle C is located to the right of the first black key in a set of two black keys that are located at the center of the piano.
Place your right index finger on the next E. This is the white key that is four half steps from C. (A half step is the distance from one note to the next note, which includes both black and white keys.)
Place your right middle finger on G, which is three half steps to the right of E.
Play C, E and G together to form a C chord.
Transform the general C chord to a C7 chord by adding a Bb. Bb is three half steps to the right of G. A seventh chord is one of the most basic blues chords. The pattern of the seventh chord is 1-3-5-7, or root note (the note you started with), four half steps, three half steps, three half steps. You create seventh chords of different types by beginning the pattern with a different note.
Play an F7 chord and a G7 chord using the same pattern above.
Practice playing the C7, F7 and G7 chords in succession. This is called a I7-IV7-V7 progression, which is a progression that is synonymous with the blues.