The question of just what it means to "twist a tune" in the style of the "new dithyramb" (delta 1029) is unclear (kappa 2649). M.L West suggests that kampai "are associated with departure from harmonia (alpha 3977), the proper attunement, and it seems likely that they are the same as what are later called metabolai, i.e. modulations" (Ancient Greek Music (Oxford 1992) 356 and n.3); but see the discussion on this word and the related keklasme/nos 'bent' (web address 1) at beta 488.
The lines quoted are from a passage on the old way of teaching schoolboys: Aristophanes, Clouds 969-71 (web address 2), with the omission of a verb for 'playing the altar-wit or fool' bwmoloxeu/saito. The verb is included in the quotations of the same verses at beta 488 and kappa 2647; for its meaning and use cf. beta 486, beta 487, beta 489, beta 490, chi 296. Clouds 961-1008 are quoted in the Anthology of Stobaeus.
[1] This gloss is presumed (by Adler and others) to stem from the scholia to Clouds 971.
[2] See phi 761 for this citharode and dithyramb poet.
[3] The text here reads the third person singular of the present imperative of tri/bw, instead of the third person singular of the imperfect indicative passive found in the text of Aristophanes and the Suda quotation at kappa 2649 (but not at beta 488). This turns the historical account of proper education in music into a moral exhortation to teachers. The verb is a strong one, suggesting schoolboy slang, appropriate to the context (web address 3).
[4] The feminine plural adjective 'many' is used here as a cognate or internal accusative, implying plhga/s 'blows', as a scholiast says (scholia recentiora 972c). See pi 1872, citing the identical construction in the Gospel of Luke (12:47), a phrase often cited in patristic writers.