C Dominant 7 Chord

C7 is a chord that consists of four notes:C,E,G,and B flat. To work this out in any key take these notes from the major scale. 1 - 3 - 5 - 7. The seventh note should then be lowered by a semitone, for example the seventh note in C Major is B natural. To play C7 you lower the B natural a semitone making it B flat.

Take another example in G major The notes 1357 in G major would be G - B - D - F sharp. Lower the 7th a semitone and you now have G - B - D - F natural = G7. Professional Pianist reviews Online Piano Courses