When selling our house we chose to not have music as we decided it was too easy to get it wrong and irritate people.
The best settings I've seen for open homes have been a nice fire on a cold winters day, or full open patio doors on a summers day, a place to sit and remove shoes and put umbrellas, any baking smell or subtle clean smell, (although smells are tricky too as I really dislike perfume smells and coffee smells, so there are bound to be people who dislike baking or clean smells), and places made as light as possible.
The worst - damp smells or dehumidifiers left out, wet dog smell or cats food bowls left out, half done washing up in the sink, a teenage boys room left 'as is' (topless posters, half made bed etc), a waterfall coming from the guttering and a very weedy garden. This were all in houses hoping to achieve prices of $750k and upwards.
Good luck - it's a tricky market to sell in, so any extra you can do will help.
Cheers
Tia