Any chord is in search of his roots. It is based on known foundations, but sometimes bass notes that are totally foreign to him. Any chord can rely on a low bass note belonguing to it, or that is completely foreign. For example, in the first case we have a C major chord, perfect major triad above a low of C note, that is the real true chord root: C-E-G. we note : C major is the note C, slash on C bass. In the second case, we have a triad of C major on a low note B. We write: C major chord, slash, on a B bass.\r\nThe chord we obtain from bottom to top: B-C-E-G, is a third inversion of the C major 7 chord: C-E-G-B. the third case, we have a minor triad C-Eb-G above an A low note. The chord obtained from bottom to top is: A-C-Eb-G,an A half-diminished seventh chord. Finally, in the last case, the chord indicated is: C major built on a Db bass , which is completely foreign to the C major tonality. Db is a non-harmonic note. This gives a rather dissonant chord, very useful in some styles of music. Listening..