Paying mahr in installments and wife claiming her mahr from husband's estate

Q: Is it allowed for the husband and wife to agree on terms/installments for the payment of mahr? Example: I'll pay you 1000 every month for 2 years. Is this OK or is it better to pay upfront one time even though it is less? 

If the husband dies, can the wife claim this remaining amount from the inheritance?

Keeping a wind chime in the garden

Q: I would like to know if it is permissible to keep a 'wind chime' in the garden? 

We moved into a house and there is a wind chime in the garden, and I am not sure if its something that we could keep, as it makes a noise when the wind picks up and the kids enjoy it, or should it be removed as the sound might be considered music?