A fascinating Ask Metafilter thread traces the history of the call-out/insult/diss song, wherein a songwriter derides other songwriters or performers. It turns out that this goes back at least to the 1830s:
The tradition of dissing, also called dozens or 'playing the dozens', goes back to the earliest days of African-American culture, if not before. The very first written citation of an African-American song in English, published in 1830, is a song of this type: Round the Corn, Sally, in which the enslaved female singer is described as dissing every member of a picnic party in skillful rhyme.
Up until very recent times, you could find rap's closest antecedent, toasting (or improvising spoken poetry, without a beat), in Southern roadhouses, and toasting often featured dissing and call-outs. For a sample of American toasting (along with a mind-blowing collection of other African American roots music traditions collected in the early 70s), you might want to view Alan Lomax's film, Land Where the Blues Began.
It's not quite what you asked, because you're looking for specific call-outs, but at least in African-American music the idea of it goes way, way back. You'll certainly find examples in the pop world , but I thought you'd want to know that it is deeply rooted in traditional oral culture.
(via A Whole Lotta Nothing)
Update: Paul sez, "Old Norse
and Old English poetry (written down in the 13th and 8th-11th
centuries respectively, but often of earlier oral origins) know the
tradition of "flyting," insulting speech esp. before battle. An Old
English example occurs in the poetic account of the Battle of Maldon
(991 AD); a fine Old
Norse example occurs in the Poetic Edda, in the poem Helgakviða
Hundingsbana fyrri between Sinfjötli and Gudmundr, containing such
insults as: 'nine wolves you and I begot on the island of Sága; I
alone was their father' (stanza 38). Since all of this is metrical
poetry, it should be seen as ancestral to insulting rap just as well
as the Afro-American types mentioned in the Ask Metafilter thread. And
I mention this only because this is my field of research; I have
little doubt that classicists could come up with other examples,
(perhaps metrical Roman graffiti insults?)."
Update 2: Amanda sez, "The Inuit have a version as well, called 'song disputes':"
"Although, as Balikci suggests in the final statement quoted, competitiveness between song partners is often discernible in their songs, this was nothing like the song dispute, a kind of forum for legal action. When an unjust action had been committed, victim and accused would gather in the dance house along with the whole community, and sing songs of derision and degradation against one another. The verdict (that is, the balance of community support) was determined partly by the very number of songs, partly by the bitterness and humour of the mockery, and partly by the justness of the cause."
Update 3: Alex sez, "This tradition actually dates from ancient Rome, taking the form of
invective speeches and poems that were commonly recited at parties. The
most famous invective poet is Catullus, from the first century AD. So
when you hear Fifty singing about how so-and-so loves the cock, you may
think this is a new thing, but it actually dates back around 2,000 years."
Update 4: John sez, "Actually, invective poetry goes all the way back to the beginnings of western literature, well before Catullus (whose dates are ca. 84-54BC). The best example is the (ancient Greek) iambic verses of Archilochus, who lived in the 7th century BC. There exists a fragmentary poem in which (if I remember correctly) he vehemently slanders a girl named Neoboule and her father and describes, in graphic detail, how he seduces her sister in revenge. But I find it's a little silly to keep searching for parallels to 'dissing', something probably common to all cultures. I seriously wonder whether the dissers of the 1830s are any more closely related to today's rap music than the ancient Greeks."
