I agree with everyone who says dressy rather than dressed down. Dress pants, dress shoes, and a button down shirt. And a pre-knotted tie in your pocket in case you get there and see that the other interviewees are in suits.
Maybe it’s a regional thing, but we’re in the Northeast and DH and DS both said very firmly, when I asked for male input just now, NO CLIP ON TIES! They shook their heads and raised their eyebrows and smiled incredulously at the idea of wearing a clip-on tie to an interview and said better not to wear a tie at all if that’s all you have. They say that clip-on ties are for kids in grade school, never for adults.
And don’t be tempted to put scotch tape on the back of the tie either.