Music Box

Blanks come from the Wizard, which means hardmode and means finding him underground first. He restocks, so filling the shelf is a money problem rather than a rarity problem. One box breaks the pattern: the Journey's End track cannot be recorded and is bought outright from the Princess once the Moon Lord is dead. It also behaves oddly, playing the full credits sequence from a real accessory slot and only the music from a vanity one.

Equip a blank in a real accessory slot and stand where a track is playing. It does not fill a bar. Every tick it rolls, and when it lands a sound plays and the blank becomes that track's box. The average wait is under ten seconds, but there is no ceiling on a bad run. A blank sitting in your inventory records nothing and neither does one in a vanity slot. If your music volume is at zero it will never record at all, which is the most common reason someone decides the item is broken.

Anything tied to a boss or an event is the hard part, because the roll needs the music to still be playing. Kill something efficiently and the theme stops before the box catches it. The fix is to stall on purpose: bring weak gear, stop attacking, and let the encounter run long. Do the same with invasions by leaving one enemy alive.

Two boxes have their own rules. The Mechdusa theme only exists in the Zenith seed, so you need that world for it. The Torch God theme is the only one a character can permanently miss, because consuming the reward removes your ability to start that event again. If you want a complete set, leave that fight alone until early hardmode when blanks first become available. A character who has not taken the reward can still trigger it in your world, and boxes copy other boxes, so neither situation is unrecoverable.

Two ways: wear one, or place it and switch it on. A placed box plays for everyone in earshot and responds to wiring, which is how you give a built area its own theme instead of accepting whatever the biome plays. Its reach is measured against your screen rather than in tiles, so a wider monitor genuinely hears one from further away. Since boxes record other boxes, covering a large build means placing one, standing beside it with blanks in your accessory slots, and spacing the copies out, rather than going back to the original source for each.

A few boxes are built out of other boxes instead of recorded, and they are the reason a full collection takes so long. The Title recipe is fussy about which variant of a track you feed it: the standard daytime and underground themes are required and their alternates will not substitute, which catches people who recorded whichever version happened to be playing. It is also awkward in a crimson world, since the recipe predates the crimson and still wants corruption tracks. The Dryad will sell you Corrupt Seeds if you talk to her inside a hardmode graveyard, and a small planted patch is enough to record both corruption themes from. Once a crafted box exists it acts like any other and can be copied.

Shimmer runs the process backwards and strips a recorded box back to blank, so a duplicate is never wasted and a mistaken recording is never permanent. A box also sells for the same amount whether it holds a track or nothing, which means selling a spare is pure loss next to blanking it and reusing it.

• Several boxes wear the wrong outfit. The one now tied to the Eye of Cthulhu is styled after the dungeon, and the Golem box is gold because it used to belong to the Pirate Invasion.
• The twelve boxes that go into the Title recipe hold the entire soundtrack as it stood in 1.1. The recipe was never updated as the game grew, so it is a snapshot of a much smaller version.
• The Otherworldly tracks come from Terraria: Otherworld, a spinoff that was cancelled.
• Exactly one track has lyrics.