Even if your primary instrument is guitar, saxophone,or timpani, a keyboard or piano can be quite useful for the study of music theory,as well as a compositional tool that can be interfaced with a Digital Audio Workstation. I am primarily a guitarist, and although I have persevered through the lean times with nothing but a computer mouse between me and my workstation, I prefer to have the option of a keyboard. A piano can expedite the creative process by providing the means to immediately explore harmonic and melodic possibilities over a 7 octave range. All that is required is two hands and ten fingers to feel the benefit.
The video tutorial I have included here features Milton Ruffin, an exceptional educator and world class artist who has performed with many musical icons of the late 20th century, and beyond. As a bassist he has performed with Lou Rawls, Eric Gale, George Clinton, Parliament Funkadelic, and Rick James, to name a few. Here he offers an excellent presentation that clearly explains the basic fundamentals of music theory. I have provided the following notation to further illustrate what is covered in this video.
In Fig. 1 the first measure consists of a C major arpeggio, or the basic C triad that is based on the root note which is C, followed by the 3rd scale degree and then the 5th scale degree. Thus, the formula for any major triad is written as 1-3-5. In the second measure the notes are stacked and played simultaneously. And so we can understand that the difference between a chord and an arpeggio is simply a matter of time; the space in-between. An arpeggio is simply the individual notes of a chord played consecutively, or one after the other. The reader will notice that beginning with the third measure I have added an extra scale degree to the arpeggio, and subsequent triad.
As illustrated in the video, when considering the C major scale, or any major scale we are only working with 7 notes; the 8th note being the octave, at which point the following 7 notes appear to sound the same as the previous 7 notes , only at a higher pitch. An octave is defined as the interval between one musical frequency. The name "octave" is derived from the Latin, "octavus" ,meaning eight. Although we often take the reality of musical octaves for granted, it is actually quite remarkable that by multiplying and accelerating the frequency by two, or by cutting the frequency in half and creating a slower vibration , we hear what appears to be the "same" sound at a higher, or lower pitch. But it is not the same sound , and the fact that we perceive it as such is a mystery that is on par with the questions of truth, knowledge, and the existence of God.
In Fig. 2 we notice the sound of the chords is not as "clear" or defined as the chords in Fig. 1, save for the first two measures. Why? Except for the C triad, the chords in Fig. 1 are all four note chords, but the fact that the note density of Fig. 2 steadily increases from 3 to 8 notes is not the reason for the claustrophobic dissonance and lack of clarity. The "problem" here is the 6th degree of the scale. Between the sixth and seventh degree of the scale is what is called a second interval. All of the other intervals are third intervals. Apparently, a third interval is more consonant, or pleasing to the ear, as it evokes a state of rest, whereas a second interval evokes a feeling of agitation, or a need to resolve itself. This is why mainstream music uses such chords and intervals sparingly, and primarily as a transitional device. And so, yet another unexplained mystery of the ages. Why do certain combinations of frequencies evoke such feelings?