How do you sell your music on iTunes? Do you market your band by volunteering at the library, hand out free T shirts at gigs, play middle school grad parties to break onto the tween scene?

If your lead singer is already famous and talented enough that your band doesn’t worry about how to sell music on iTunes, you’re probably One Direction or U2. Thank Bono for his venerated vocal chords, and the fact that your music is flying off of music distributors’ virtual shelves without you ever needing to Google search “how to sell music on iTunes.” If you have the voice of an angel, you’re among a lucky few.

But besides the fame, the hype and the fan girls, have you ever considered what vocal quality sets singers apart? Is a singer’s vocal talent measurable, or does “good” singing fall into the same intangible gray area as fine art, quality of cologne, and the legal definition of pornography?

Although musical styles and preferences vary greatly by culture, continent, era and audience, mankind can usually reach a general consensus about what singing is noteworthy and which artists’ voices just don’t make the cut. Because although William Hung totally should totally have made it to LA because he was born for the limelight (after 2006 you thought you’d never hear another William Hung reference, didn’t you?), everyone knows the problem. His voice, to put it simply, is rubbish.

In 2008, Freakonomics.com quoted a study by the Acoustical Society of America surveying singing quality in the general population. According to the study’s findings, most amateur singers can carry a tune as accurately as trained, professional singers when singing the same song at a slow tempo, suggesting that “singing appears to be a universal human trait.” However, the occasional singers had a higher rate of pitch errors than the professionals, “suggesting the existence of a purely vocal form of tone deafness.”

But while perfect pitch makes superstars like Maria Carey and Michael Jackson, there are plenty of acclaimed artists riding their flawed, non-perfectly-pitched vocal talent to the bank. Taylor Swift, Justin Bieber, Selena Gomez, Rihanna: all very famous songsters without conventionally “good” voices. And so, perhaps a better question to ask when judging the quality of a lead singer is not how do we define good singing, but “does the voice suit the task?”

Consider Taylor Swift’s performance at the Grammys in February. Swift, who has long received criticism for her flat, thin and shaky voice in live performances, was dressed as a circus ringmaster and performed “We Are Never Ever Getting Back Together” (and received mixed reviews).  But Swift’s girl-next-door persona, bubbly youth and lyrical intimacy passably compensates for her weaknesses —making the song undeniably well suited for her.

If this reference is too teeny-bopper for you, consider Bob Dylan or Neil Young. Did either man have perfect pitch? Absolutely not. Did either man encompass almost every popular American style as legends in their time? Yes.

If your lead singer embraces your tunes, embodies the genre and has a kick-ass persona the crowd loves, don’t stress about his or her lack of perfect pitch. How do you sell your music on iTunes? Not by being unoriginal. We know this sounds like something overheard on Sesame Street, but it’s up to your band to determine what makes a good singer.