I was listening to a fairly obscure piece called "Rats in Spats" by the Combustion Collective and it sounds (I'm not a musician) dissonant somehow. Can the rhythm section play in a different key than the lead? Just curious. Don't get too technical
Thank you
Sounds like regular funk to me with some effects on one of the guitars. If you want to hear dissonant music, listen to Arab on Radar, Penderecki or Xenakis. This or the other way 'round, "dissonance" is a pretty subjective term, and it's changed over the years. Stravinsky's earlier works were considered "dissonant" by the public when they were released but do not sound dissonant to the average modern listener.
Under "traditional" music theory, dissonances are defined as certain pitch/frequency distances between 2 or more notes played at the same time or in quick succession. Those "rules" have been broken time and again in the last ~100-150 years, as the human ear got more and more used to those note combinations being played. Dissonances are pretty common even in earlier genres like blues and rock'n'roll and even more prevalent in modern jazz and metal music.
Whether or not 2+ notes played at the same time or in quick succession sound "dissonant" also depends on whether the instruments playing them "have similar soundwaves" and play in the same frequency range (in more complicated words, it depends on the overtones an instrument produces when a note is being played). Compare, for example, a minor second played on 2 electric guitars to a minor second played on guitar and saxophone.
The notion of "dissonance" is culture-dependent as well. I am assuming we are talking about Western Composition here. Because the quarter-tone scales common in the East might sound dissonant to a Western listener too.
Consider a simple passage with two notes played on very plain-sounding instruments. Those two notes may be related in one of the following 3 ways:
Unison. They have the same frequency.
Consonant. They have related frequencies, i.e. are multiples of one another. For example. notes at an octave have a frequency ratio of 1:2, and perfect fifth have the ratio 3:2.
Dissonant. Their frequencies are not related, or the relationship is difficult for the human ear to suss out. For example, notes at a tritone interval have a ratio of 45:32.
That's the basics. It gets more complicated when you consider that most instruments produce overtones, which also have frequency relationships. Also, psychoacoustics is an issue: you can fool the ear into thinking things are consonant or dissonant by manipulating the context, e.g. their rhythmic position or role within a larger more complicated pattern of harmonies. But basic dissonance is really just about the conflict of audio frequencies and your ear's ability to perceive them.
...I'm not a musician ...Don't get too technical
It difficult to answer without being technical.
Defining dissonance breaks down into two general approaches. One tries to consider it an acoustically matter, the other treats it as a stylistic/cultural matter.
Acoustically, dissonance is a sliding scale that looks at the ratio between two pitches placing simple ratios on the consonant end of the scale and progressively complex ratios toward the dissonant end of the scale. A perfect unison of two exactly the same pitches (1:1) is the simplest ratio and consonant. An octave (2:1) is simpler that a perfect fifth (3:2) and considered more consonant. And so on with other pitch combinations.
Stylistically, dissonance is more a matter of music conventions. Consonances and dissonances are defined in a not necessarily scientific way. Musicians use defined dissonances and adhere to stylistic conventions in varying degrees. Audiences respond to the music mostly as a matter of musical culture. A musician may conventionally resolve a dissonant fourth to a consonant third while the audience hears it as a sort of anticipation of a delayed ending, perhaps like the release of a held breathe.
With that background we can compare a perfect fourth (4:3) and a major third (5:4). Acoustically the perfect fourth is more consonant that the major third. Stylistically, the fourth was consonant during the Middle Ages but a dissonance in the 18th Century.
How is dissonance created?
Without going into greater technical detail, you can probably see now that there isn't a single answer. In the end it's prescriptive based on whatever system you are using. It's a tautology. Dissonance is created by playing that which is defined as a dissonance.
