Angel P. answered 04/30/19
Individual Education Specialist; Homeschool solutions for everyone!
Seventh chords are the very beginning of what we call "color chords." They naturally lead us into the next chord in the the chord progression. You certainly can play a song without sevenths (most of the time), but a song loses its vibrancy and color. Learning 7th chords also leads the way to understanding augmented chords, sustained chords, 9th chords, 13th chords, etc.
Consider that music is another method of communication, just like reading or speaking. When you learn to read, at first you are fine with "See Jane run" and other such simplicity. But as your reading progresses, you develop a much better picture when you read, "In her bright red athletic top, Jane sprinted down the path as though the hounds of hell were after her."
Simple chords with their root, 3rd, and 5th are great. They are fine on their own. However, when you add what we call "color chords" to them (7ths, 9ths, 2nds, 13ths, augmented, sustained, etc) you begin to create mood and meaning that a simple melody with a basic chord cannot convey. Don't give up! You'll begin to hear the difference and see how it adds to your playing!
Katherine S.The Maj7 (for example C to B) will function very differently from Min7 (C to Bb). The 'point' is color, texture, 7th chords are extension of the triad. Maj 7 has a soothing sound verses Min 7 (think bluesy sounds). You may want to experiment with "voicings" the order in which you play the chord. That too can change the feel. Traditional triads are pleasing too and serve a different purpose depending on the song.
Norman R.The voice leading of major and minor 7th chords adds another layer of harmonic interest. An A minor 7 chord followed by a D major chord can resolve the 7th degree of the 1st chord (G in A minor 7) to the 3rd degree of the D chord (F#) by moving down a half step. These little events add to the aesthetic appreciation of a chord progression.