This is a fluorescence-based recording of the third movement from Mozart's horn concerto no. 4 in E flat major. Dennis Brain's classic 1953 rendition of the opening horn solo was played back with the speaker pointed at the single-particle tracking microscope described in http://dx.doi.org/10.1021/nl1028792 and http://dx.doi.org/10.1063/1.4803538. The induced motion of a 200 nm yellow-green fluorescent bead fixed to a coverslip was tracked at a frame rate of 3.2 kHz. The obtained trajectory was processed by taking the L1 norm, baseline-subtracting and normalizing the signal, and converting it to a wave file. Note the pleasant underwater-like ambiance due to the natural lowpass filter applied by the microscope. Inquire if you are interested in using fluorescence microphones in your recording studio.

mjuette