▁Sur co ▁( f ounded ▁ 1 9 3 0 ) ▁and ▁Ult ra ▁( 1 9 3 6 – 4 7 ), ▁both ▁journ als ▁that ▁provided ▁comment ary ▁on ▁foreign ▁journ als . ▁In ▁ 1 9 3 7 ▁he ▁founded ▁the ▁Soci edad ▁de ▁Est ud ios ▁Af roc ub anos ▁( So ci ety ▁of ▁Af ro - C ub an ▁Studies ) ▁and ▁the ▁journal ▁Est ud ios ▁Af roc ub anos ▁( A f ro - C ub an ▁Studies ). ▁ ▁He ▁helped ▁found ▁the ▁journ als ▁Rev ista ▁B im estre ▁Cub ana , ▁Archiv os ▁del ▁Fol kl ore ▁Cub ano , ▁and ▁Est ud ios ▁Af roc ub anos . ▁ ▁Ort iz ▁also ▁developed ▁a ▁theory ▁of ▁activ ism ▁within ▁Cuba ' s ▁political ▁system . ▁He ▁said ▁that ▁Af ro - C ub ans ▁had ▁been ▁character ized ▁neg atively ▁based ▁on ▁their ▁African ▁descent , ▁and ▁tra its ▁said ▁to ▁be ▁" prim itive ." ▁He ▁wanted ▁to ▁show ▁the ▁true ▁nature ▁of ▁their ▁culture : ▁its ▁language , ▁music ▁and ▁other ▁arts . ▁▁ ▁His ▁books , ▁La ▁African ia ▁de ▁la ▁Mus ica ▁Fol k lor ica ▁de ▁Cuba ▁( 1 9 5 0 ), ▁and ▁Los ▁Inst rument os ▁de ▁la ▁Mus ica ▁Af roc ub ana ▁( 1 9 5 2 ▁- ▁ 1 9 5 5 ) ▁are ▁still ▁regarded ▁as ▁key ▁references ▁in ▁the ▁study ▁of ▁Af ro - C ub an ▁music .