DJ mode

The player has two modes: NORMAL for ordinary playback and DJ for automatically mixed sets.

DJ is Soundsible’s built-in automatic DJ. It does not put a crossfade on a shuffled queue. It builds an editable musical route, analyses how each pair can meet, prepares the incoming track on a second deck, and performs the handoff at a chosen cue point.

DJ mode is currently labelled beta in the player. Its core mixing and route workflow is available now; the label sets the expectation that its planning and interface are still being refined.

Start a set

• With nothing playing, press Start a DJ session in the bottom player, then choose music. The DJ chooses an opening from that selection and starts the route there.
• With a track playing, open the player and switch from NORMAL to DJ. The current track becomes the first visible influence in Session.
• In Session, use Mix with… to add an influence or Change… to choose a new direction using the same music browser.

The three parts of the workspace have separate jobs:

What the DJ listens for

When a track can be analysed, Soundsible measures its tempo and beat grid, key, energy, musical sections, intro, and outro. It uses those features both to order candidates and to choose a transition. Depending on the material and DJ style, the two-deck engine can perform:

• beatmatched long blends;
• bass swaps and filter blends;
• echo cuts and structural cuts;
• conservative fades when the analysis is missing or a more elaborate mix would sound worse.

The engine limits tempo stretching and falls back safely instead of forcing two incompatible recordings together. Loudness levelling sits inside the same program path, so a transition does not need a sudden volume jump to feel alive.

Make the set yours

• Add to session requests specific songs without changing the musical direction.
• Mix into session adds an influence alongside the existing ones.
• Change session replaces the influences and automatic recommendations while preserving your requested songs and their relative order. The current song continues; an already audible blend finishes. Preparation failures leave the previous session intact and offer Retry in the Session block.
• The Session block shows the active influences. Remove an influence while another remains, or use Change… to replace the last one.
• Place a must-play track. Add a song to the Route or drop it into a particular gap. Soundsible may insert a bridge when that produces a safer path to the request.
• Reorder freely. Moving tracks changes the route immediately. Joins that no longer match their original transition use a plain fade until you press Fix mix.
• Repair without losing your choices. Fix mix rebuilds transitions and generated bridges around the tracks you placed while keeping those tracks in their chosen order and depth.
• Skip without leaving DJ. Next asks the DJ for a short handoff to the next route item instead of dropping back to ordinary playback.
• Choose music from anywhere. Song and collection menus offer the same session actions. Play now remains an explicit immediate handoff. Choosing a musical influence does not also request that exact song.

DJ keeps explicit requests ahead of generated music. Leaving DJ removes its generated branches and bridges, but tracks you explicitly placed survive as a normal manual queue.

The NORMAL / DJ badge in the mini-player always shows who owns playback. The choice is sticky for the current listening session and is included in session handoff state. Only selecting NORMAL explicitly, or accepting the prompt shown before starting incompatible Podcast or Radio playback, leaves DJ mode. If another song is selected while a blend is already audible, that blend finishes and the most recent selection is mixed next.

DJ, Radio, and Autoplay are different

DJ explores the active influences together with the last four automatic songs that actually started playing in the current direction. A pending recommendation is not a discovery root. Exact requests and bridges do not become roots just because they played. Mix with… retains this exploration; Change… clears it when the new direction is committed, without promoting the outgoing song. These discovery roots do not appear as additional influences in Session.

Changing direction prepares a replacement while the existing session continues playing and refilling. The new influences, exploration revision and automatic route take effect together. Failed preparation retains the previous session.

If a provider request fails temporarily, DJ retries with increasing delays. If no new candidates remain, DJ stops repeating the same search and offers Retry. New influences, exploration roots or exclusions make planning eligible again. Existing playable route entries continue normally in either case.

Session snapshots preserve exploration separately from repeat history. Older snapshots keep their queue and requests, but history without reliable direction provenance is not promoted to exploration.

Continuity validation

A deterministic regression exercises thirty successive routes with overlapping recommendation neighbourhoods, plus independent tests for direction changes, request isolation, interrupted preparation and exhausted-input retry behaviour. A read-only local replay across 204 library tracks and cached related results produced 1,090 route extensions with both the repaired selector and the baseline at 2b5a365, compared with 972 at 34d95f1. Four tracks had no initial route in all three runs. Missing cache entries were treated as empty; no live provider requests or audio playback were performed. This checks selection continuity, not audible transition quality or physical-device playback.

Broadcast the result

Live captures the program bus after both decks, loudness levelling, EQ, filters, crossfade, and echo. Listeners therefore hear the same DJ set that the DJ hears, not a separate approximation. See Live for HTTPS and room setup.

Privacy and storage

Audio analysis is local. Soundsible stores compact measured features in its DJ cache, not decoded copies of the audio. Listening history and recommendation signals remain scoped to the account on your Station.

The detailed queue and route rules are recorded in Playback queue contract. Implementation and data flow are described in Architecture.