Shakespeare's Sonnets: Music to hear, why hear'st thou music sadly?

Music to hear, why hear'st thou music sadly?Sweets with sweets war not, joy delights in joy:Why lov'st thou that which thou receiv'st not gladly,Or else receiv'st with pleasure thine annoy?If the true concord of well-tunèd sounds,By unions married do offend thine ear,They do but sweetly chide thee, who confoundsIn singleness the parts that thou should'st bear:Mark how one string, sweet husband to an other,Strikes each in each by mutual ordering,Resembling sire, and child, and happy mother,Who all-in-one one pleasing note do sing Whose speechless song being many, seeming one, Sings this to thee, "thou single wilt prove none."