QR Codes in the Library is an initiative of the Loeb Music Library to post QR codes in the stacks that link to related subject research guides. In addition to the generation and posting of the codes, the project implementation included successful testing of subject guides for mobile compatibility, verifying mobile signal strength in the area where signs were posted, and putting analytics in place to track impact on guide usage. Usage has remained consistently low for the three years following implementation, making the codes an easy and extremely low-cost method of linking physical and digital space, but one with correspondingly low impact.