The industry-standard Compact Cassette brought portable, affordable analog audio to the masses: ⅛-inch (3.81 mm) magnetic tape, two sides (A/B), common lengths C60/C90/C120, and tape formulations Type I (ferric), Type II (chrome), Type III (ferri-chrome, rare), Type IV (metal). Paired with Dolby B/C/S noise reduction and HX Pro, cassettes powered the era of Walkman, boomboxes, home decks, and car stereos—easy to record, swap, and archive music, mixes, and voice notes.
