It seems as if one of the objectives of this book should be to reveal what the difference is between “good” music and “bad” music. However, if you have read this entire book and still have no idea, don’t worry—the authors don’t know either. Or, at least, we are not able to make any generalizations about what is good and what is not, even if we are adept at identifying quality in specific instances. This is because music is so diverse in its forms and objectives that there cannot be a single standard of quality. When we ask, “Is this music good?,” what are we asking? Although this particular question is vague and unhelpful, asking questions can help us to judge the quality of a specific composition or performance.

First, we should think about the purpose behind a given composition. Is it supposed to make people dance? Is it supposed to provoke an emotional reaction? Is it supposed to make listeners feel patriotic? Is it supposed to incite rebellion? Is it supposed to be intellectually engaging? Then we should ask the question, “Is this piece of music successful at achieving its objective?” This way we can avoid pointless comparisons between pieces of music that serve completely different functions. There is no value in saying that a symphony by Beethoven is “better” than an Appalachian fiddle tune.

Second, we can measure a composition against others of its type. While it is misguided to compare a Bach cantata to a hip-hop track, we can argue that Bach wrote better cantatas than other 18th-century German church composers, or that Ice-T is a better rapper than Vanilla Ice. To do so, we need to agree on some specific criteria used to determine quality. This is very difficult. Most classical musicians agree that Bach is the greatest composer of his era, if not of all time. They will argue that his music is better than that of his contemporaries because it is more complex, or more expressive. But who decided that complexity and expressivity were desirable qualities? Bach was not highly regarded in his own time, when listeners preferred a more restrained approach to composition. Should that matter to us today? There’s a further problem. Although Bach’s music was not widely studied or performed until eighty years after his death, it now forms the bedrock of the classical music industry and educational system. Can those of us who grew up playing and listening to Bach’s music judge its quality, when that same music has been used to define and teach “goodness” in classical music? Or are we only able to judge less familiar composers in comparison to Bach?

Third, we might compare a piece of music to others of its kind by considering originality. When we find a pop song or a string quartet or a gamelan composition that we really love, we are probably attracted to it because, while representative of its type, it is somehow different in an appealing way. All songs played on Top 40 radio have a great deal in common, but a “good” song is likely to have something special that sets it apart from the others. All string quartets composed in the 18th century will share formal and stylistic features, but a “good” one will stand out as unique. What it means to be original and how innovations might be received will depend on the type of music.

Fourth, we can consider the skill of the composer or performer. Certain types of music—four-voice fugues, for example—are objectively difficult to craft, and we can empirically judge their quality. However, this is often not the case, as this type of evaluation requires strict criteria. We can also judge the skill with which music is performed. In the classical tradition, we tend to separate the quality of a performance from the quality of the music being performed. In other traditions, however, such is often not the case. The music of John Coltrane is “good” not because he wrote exceptional tunes but because his recordings are extraordinary. If he had spent his career publishing printed music, no-one would have noticed. Because he worked with a team of highly-skilled musicians to record and release groundbreaking performances, however, we hold his music in high esteem. And how do we know that his recordings are “good”? This again requires some level of agreement between members of the jazz community concerning the goals of their music.

Finally, we can take into account the impact that music has on listeners and society. We can argue that “good” music is important to someone, or plays a role in the development of art or culture. It has certainly been argued that the music of Wagner is “good” because it heavily influenced the next generation of composers. It has also been argued that Wagner is a “good” composer because many people love his operas. However, influence and popularity are often determined by factors that are independent of the music itself. Wagner happened to be a German male (which allowed him to be taken seriously) with a royal patron (which allowed him to focus on his work and to stage lavish productions of his most ambitious operas). These circumstances contributed significantly to his legacy. If Wagner had written all of the same operas, but they had never been staged and were forgotten today, would those operas still be “good”? Were there other composers writing at the same time who, due to less fortunate circumstances, have been forgotten, but who’s music was just as “good” or “better”? Is it even possible to know? To turn to another example, young people are often criticized for listening to “bad” (that is, popular and ephemeral) music. This has been going on for many generations, but no amount of criticism can stop anyone from listening to music that they love and that has meaning for them. Does the fact that a piece of music is important to someone make it “good”?

As these questions reveal, it is no easy task to determine whether a piece of music is “good” or not. It is tempting to paraphrase the words of Supreme Court Justice Potter Stewart, who famously declined to define pornography in a 1964 decision but instead stated “I know it when I see it.” Many of us would like to say of good music, “I know it when I hear it”—and sometimes we do. However, we should never forget the limitations of our individual perspectives, and we should keep our ears open to all of the good music that is waiting to be discovered.