Some pranks are instantaneous, while others are a slow type of torment that builds until the prankee breaks. What we now refer to as the stereo prank falls under that category. While Nate was out of town, we installed two speakers in the ceiling and aligned them to the left and the right of where his chair sits - allowing for the sound to appear uniform. We "drilled" a small hole in the wall and ran the speaker wires to the stereo we had hidden on the upper shelf in the adjacent computer room. With this setup, we were able to control both the musical selection and the volume of said music. This prank lasted significantly longer than we had expected, as Nate suffered in silence and apparently managed to come up with some justification for the source of the noise - even the three days we left the spanish station playing.
It should be noted that Nate's lack of complaining does not mean he was not constantly hearing the music. On the contrary, the group could easily tell when the music was playing, as Nate would spend very little time in his office and more time in the lab space. This caused some dissent among the grad students and led to a temporary shutting down of the music, to allow for a breather time for the students and postdocs. However, Nate was kind enough to regale us with tales of the pranks that he played back in his day and taunt us for our lack of pranktivity. The music was turned back on and the volume level was raised up and down over a few days. Gloria Gaynor's "I Will Survive" was played on repeat for a day and a half. Finally, one day, Nate cracked. He stormed (as much as Nate ever storms:) upstairs and downstairs searching for someone to blame for the source of the music. He even called Paul Carroad in the adminstrative office. We finally had the justification for moving ahead.
We created a subliminal CD that we played very softly on repeat and raised the volume slowly over two days until the sound was very apparent. Nate took this first prank quite well and he was obviously pleased that we thought enough of him to torment him.