Original hand colored engraved sheet music by George Bickham sell for a high average of $150 - $300. The suggested insurance or replacement value is $400.
Here is a link for you to comparables being sold by a print dealer:
Here is a link for you to a sheet that sold for $240:
There are 6 prints listed on this link:
of which they each have G. Bickham in plate.
These prints were all pages from an 18th century book titled "The Musical Entertainer". It is typical for print dealers to disseminate book pages as individual framed prints.
Please let me know if you need further clarification or information on the value of your print.