Musician is dressed in white and playing keyboard with band.
The musician started the band.
Nothing about being dressed in white and playing keyboard with band implies that a musician started the band.
exists e1 s1 s2 x1 x2 x3.(with(e1,x3) & n_band(x3) & in(e1,x2) & n_keyboard(x2) & a_playing(s2) & Theme(s2,x2) & a_white(s1) & Theme(s1,x2) & Theme(e1,x1) & v_dress(e1) & n_musician(x1))
exists e1 x1 x2.(n_band(x2) & n_musician(x1) & Theme(e1,x2) & Actor(e1,x1) & v_start(e1))