The only mention of IQ in the original article by Lutz Jäncke ("Music drives brain plasticity") is a reference to another study " Glenn Schellenberg [37] uncove

The only mention of IQ in the original article by Lutz Jäncke ("Music drives brain plasticity") is a reference to another study " Glenn Schellenberg [37] uncovered a greater IQ increase in children enrolled in music classes compared with well-matched children who received no musical lessons". However it's hardly news that popular articles exaggerate findings in journals.