How to sync lyrics to a song without an acapella

Why an acapella used to be the requirement

Automatic timing matches the words you supply against what it hears, and in a finished mix the voice sits under drums, bass, guitars and reverb. The old workaround was to find or make an acapella first, which was a dead end for most people making a lyric video, because they had only the master.

The workflow

• Start from the best master you have. A lossless file or a high bitrate MP3 is fine. There is no benefit to converting formats first.
• Get your lyrics exactly right before you start. This matters more than anything else on this page. See below.
• Upload the mix and let the tool time your lyrics.
• Listen back to the timed result. Sections that sound unclear are where the timing will be weakest.
• Play it through and correct. Expect to move some words. Treat the output as a strong start, not a finished file.

Your lyrics have to match the recording

This is the most common cause of a bad result, and it has nothing to do with the audio. Automatic timing places the words you give it. It does not transcribe, invent a word you did not supply or skip one you did.

So a lyric sheet from the internet will often be wrong in ways that matter:

• Ad libs and background vocals that are sung but not written down
• A repeated chorus written once with a repeat instruction
• Lyrics for the album version when you are working on the radio edit
• Section labels like Verse or Chorus left in as if they were sung
• A producer tag or spoken intro that is not in the text at all

Each of these pushes the surrounding words out of place. Ten minutes checking the lyrics against the actual recording is the most valuable thing you can do.

What still makes a track hard

A finished mix is enough to start. It does not make an unclear recording clear, and it tells the system nothing about words it was never given.

• Dense or heavily processed mixes. Heavy compression, saturation and thick reverb make words harder to place.
• Several voices at once. Stacked harmonies and call and response sections give the system more than one thing to follow.
• Whispered, shouted or growled delivery. Anything far from ordinary singing is harder.
• Long gaps in the vocal. Timing tends to drift where there is nothing to anchor to.
• The wrong language, or an unsupported one. English, French, German, Italian and Spanish are supported, and you pick the language when you upload. It decides how the words are pronounced for alignment, so a track aligned as the wrong language will come out wrong. Italian has had less testing than the other four. Anything else, including any language written in a script other than the Latin alphabet, is not supported.

What you get at the end

A start and end time for every word and every line, which you can export as captions for an editor, data for your own animation or a lyrics file for a player.

Next: word level vs line level timing and SRT vs LRC.