good question...as kat laughing has been able to be the recipient of her father's fiddle this has started me thinking about this too.
I believe a "last will and testament" is official enough if signed by yourself and perhas another witness...there are forms at the stationery store which can be used for legal purposes...it is important that someone knows your wishes...and so keep this piece of paper somwhere safe and tell next of kin where to find it! and hope that there is an appropriate person to receive the musical instruments, etc. i know some families have sold instruments...such as johnny cash's to cover debts, etc. I have known of property that kids inherited and they did not want it...jsut the money it could bring...