All thirty visualizer styles with a picture of each, which ones are free, and how to choose the set that plays.
Choosing which visuals play
Open Settings › Visualizations.
Under Scenes, move through the grid. Highlighting a scene previews it; pressing the center ticks or unticks it. Ticked scenes are the ones Auto cycles through in the music room, and the ones offered in its style menu.
Turn All Scenes On or Off at the top saves ticking one at a time.
Settings › Visualizations.
Eleven scenes are free. The rest come with Theatrium Pro and show a small PRO mark.
Calm
Aurora. Free. Slow curtains of light, like the northern lights.Ocean. Free. Soft pools of light drifting like something seen underwater.Line Ribbons. Free. Fine threads drifting across the screen.Interference. Pro. Overlapping waves making shifting patterns.
From the album cover
These pick up the colors of the song's own artwork.
Silk. Free. The cover flows like fabric.Prism. Pro. The cover fractured and glitching.Liquid Sand. Pro. The cover pours and settles.Gallery. Pro. The cover rebuilt in shifting pieces.
Retro
Mixtape. Free. A cassette whose reels turn with the track.Click Wheel. Pro. A music player of a certain age, scrolling with the song.Compact Disc. Pro. A spinning disc catching the light.Lava Lamp. Pro. Slow blobs of color rising and falling.Mirrorball. Pro. Spots of light sweeping the room.
Bars and brand
Logo Bars. Free. The Theatrium bars rising with the song.Bar Wall. Free. A wall of bars in the song's colors.Bar Halo. Free. Bars arranged in a ring.Theatrium Ribbon. Free. A ribbon of the brand's colors.
Fractals
Endless mathematical patterns that zoom and turn.
Julia Morph. Free.Fractal Spiral. Pro.Burning Ship. Pro.Newton. Pro.Phoenix. Pro.
Kinetic and neon
Mandala. Free. Turning rings and spokes, in the song's colors.Kaleidoscope. Pro.Butterfly. Pro. Wings of color opening and closing.Fire. Pro. Flames that breathe with the song.Neon. Pro. Glowing tubes of light.Neon Grid. Pro. A glowing grid rushing toward you.Circuit Traces. Pro. Light running along circuit-board paths.Iron Filings. Pro. Rings of particles pulled about as if by a magnet.
Two engines
Settings › Visualizations › Visualizer Engine offers Live GPU (the visuals are drawn live on the Apple TV, the normal choice) and Video Loops (Pro: pre-made video, downloaded once, for an older Apple TV that struggles to draw them live). Once downloaded, a Remove downloaded loops button frees the space again.