Add music to presentation slides, and to the live room

Music, voiceover and effects on separate tracks

The structural difference is the whole point: instead of one background song dropped behind the whole deck, you get a multi-track audio timeline. Music, voiceover and sound effects each live on their own lane, positioned independently against the same playhead the animation runs on — so sound and motion line up by construction rather than by luck.

A working example makes it concrete. A bed of music sits on the bottom lane at low volume; an imported voiceover runs over the top on its own track; a whoosh sits on a third lane, dropped exactly where a shape enters the slide so the sound and the movement hit together. One thing to plan for: audio is imported, not recorded here. There is no in-editor voice recorder, so a voiceover has to be captured in whatever you already use and brought in as a file.

Trim, split and fade without leaving the deck

The editing verbs are all on the clip itself. Drag either edge to trim it to length, split it at the playhead to cut one clip into two, add a fade in and a fade out, and set the volume for that clip on its own. None of it sends you to a separate audio editor and back.

One honesty note that belongs in plain sight rather than the small print: the waveform stripe drawn on each clip is decorative. It looks the same for every file, so it tells you nothing about where the beats actually are — it is not a guide for cutting on the beat. Trim by ear instead: scrub the playhead, listen, and split at the point you want. Precise audio editing is entirely possible here; it just is not something you do by eye.

Place a sound left or right in the stereo field

Each clip can be placed left or right in the stereo field, not just centred. That is more than a nicety: a sound effect can enter from the same side a shape slides in from, and a voiceover can be nudged off-centre so it separates cleanly from a music bed sitting in the middle. Small placements like these are what make a mix sound arranged rather than piled up.

The limit is worth stating up front so it reads as engineering honesty rather than a surprise: stereo placement works on media you have imported into the app, and it is switched off — with an explanation shown right there in the interface — for media referenced by an external link. The reason is simple: the app controls the audio it holds, and cannot reliably pan a file it is only pointing at somewhere else.

Import once, reuse in every deck

Anything you import — audio, images, video — is stored with your account and lands in a media library rail you can pull from across every slide, every deck and every session. Import the same file twice and it costs nothing; the library recognises it. So the track you spent an evening trimming is available in the next deck without re-uploading it.

Two honest boundaries. What travels to the audience is only what is on the deck: attendees see and hear the real media in the slides you present, while the rest of your library stays private to you. And the library is a flat rail — there are no folders, no delete button and no storage-quota meter, so do not plan a filing system around it.

Timing the slide to the music, not the other way round

Per-slide timing is really an audio tool in disguise. Set a slide to auto-advance on a timer when you want the deck to run to the music on its own, and set it to hold for a click when you are speaking over it and the music is just underneath. That single switch decides whether the deck follows the soundtrack or follows you.

The practical rule falls out of that: for an unattended loop — a booth, a lobby screen — build the audio first and time the slides to it. For a talk, build the animation first and let the music sit under your pacing. And a warning worth heeding: auto-advance in front of a live audience is usually the wrong combination, because the deck will march on whether or not the room is still with you.

What happens to your soundtrack when you go live

This is the part no slide tool has. Press Present and the deck becomes a live session; your audience joins by code or QR with no account, and the soundtrack you built plays as part of the deck on their own device, in step with your control. The mix you arranged is not a preview you keep to yourself — the room hears it.

Because your microphone is running alongside the deck, each viewer independently sets how loud your voice is against the deck’s own audio, on their device. That is the control that stops a music bed from burying you on somebody else’s laptop speakers, without you having to guess a single right level for everyone. And it names the constraint one more time: a live session is the only way your soundtrack ever reaches anyone, because nothing about the deck can be exported, bounced to an audio file, or handed over as a link.