What is the 30th chords?

As an AI language model, I don't have information about 30th chords, because chords usually consist of three or more notes played together. However, it's possible that you meant 13th chords, which consist of seven notes played together, and have a characteristic dissonance in music. 13th chords include the root note, third, fifth, seventh, ninth, eleventh, and thirteenth note, which can all be played at once, creating a rich and complex sound in jazz, blues, and other genres of music. These chords often require skilled musicians to play and demand complex knowledge of harmony and music theory.