Really interesting. I have heard that a 4-track was used but never knew any of the details (like the brand of recorder or mics). I listened to Nebraska (on cassette at that) a few years after it was released and, though it hit me as unique because of its stripped down approach, I never thought it had a distractingly bad sound quality to it. I guess it shows what decent songs, "good" mistakes, and professional mastering can do for a 4-track recording (my favorite song on Nebraska is "Used Cars").