I arrange music, but i just thought; do i need permission from the composer / publisher to arrange music? For example, if i arrange Alla Turca for an orchestra, do i need permission? Or just to put Mozart Arr. (my name)

Thanks

For composers long dead like Mozart you certainly don't need permission. Just check it's not another arrangement by a composer in copyright. I think it is 70 years since the composer's death music remains in copyright, but do check. I guess it would depend what purpose you were arranging for. Public performance, wide audience, high pay, yes you would (if comoser still in copyright). For personal study or maybe your own group it shouldn't matter.

oh no, there not for performance. Just stuff i get bored with and fancy hearing it played by something else, that and it its great for sightreading

Just out of interest, bearing in mind that for legal purposes proof would be required, how would you go about getting Mozart's permission?