You have to add the instrument table one time for each link. So if you have three fields for instruments, you have to add the instrument table three times, with one link to one field for each table.
Then, when you add the Instrument Name value from the Instruments table, you can give it an alias to differentiate from the others. Otherwise, Access will use the Tablename.Fieldname format for your field name, which is not ideal.
For example, for your instance of the Instrument table that is linked to the first field, you can call it "Instrument 1." So in the Instrument Name field from the first Instrument table instance, you'd put:
Code:
Instrument 1: [Instrument Name]
to give it the "Instrument 1" alias (and assuming the field is called "Instrument Name" of course).
That being said, a better approach would be to just use a child table for your instruments, instead of having three fields. That way, you could enter as many instruments as you'd like, and you'd only have to deal with one field instead of three.