Everything Smart678 does

The full list, in plain language. New features ship steadily, so this page grows.

Editing the music

Trim a song to any length. Remove intros, verses, or whole sections and keep only what the routine needs.
Every cut lands on the beat. Smart678 finds the tempo and the beat grid, so edits snap to the count instead of landing in the middle of a phrase.
The song’s structure, mapped for you. Sections like intro, verse, and chorus are labeled automatically, so you can see where to cut instead of hunting by ear.
Marks your routine’s real length. Two draggable markers set where the music starts and where the final pose lands, and the display counts that danced length, not the whole file. Your download is named by it too.
Smooth joins or clean cuts. Every edit point is either an invisible crossfade or a tight hard cut, with no clicks or pops.
See the edit and the result. Skip view shows what you’re removing; Result view plays the finished piece.
Every cut shows how it sits on the count. On-the-count cuts read neutral, and anything that drifts off the count is flagged in amber or red with a plain-English note, so you always know before you download.
Audition before you commit. Double-click a cut to hear the original music again, then put the cut back or remove it for good.
Set the tempo your way. Tap the tempo, place the downbeat, and choose the time signature when you want manual control.
Undo, redo, and constant auto-save. Nothing is ever lost.
Trim or pad the head and tail. Add or remove silence at the start and end of the song.

Scrub the bad words out. Take specific words out of a song so it’s clean for kids to rehearse and perform anywhere.
One-click instrumental. Mute all the vocals instantly and download the instrumental.
One-click a cappella. Keep only the vocal, with any scrubs applied, and download the vocal-only track.

Change the tempo, keep the pitch.

Speed a song up or slow it down. The song keeps its natural pitch at any speed.
Each instrument gets its own treatment. Drums are processed separately so the beat stays crisp while vocals stay clear. It mirrors what a professional audio engineer does by hand.
Dial it by BPM or by percentage. From 75% to 125% of the original tempo, in clean whole-BPM steps or exact typed values.
One click back to the original speed. Instant.

Put songs together into one mix. Combine two to twenty songs (or any audio files) into a single soundtrack for one routine.
Transitions snap to the downbeats. The next song lines up automatically, and a draggable marker picks exactly which downbeat it joins on.
Each song keeps the full editor. Every song in a mix is its own copy of the edit it came from: trim it, clean it, change its speed, shape its volume, without touching the original in your list.
Match tempos between songs. Each song in the mix has its own speed control, so two songs can meet at the same tempo.
Volume lines on every track. Fade one song out under the next exactly the way you want it.
Transition sounds. Five original risers. Drag one onto the timeline and its end lands right on the transition.
Solo and mute any track. Hear one song alone, or play the mix without the transition sounds. Whatever you silence stays out of the download too.
What you hear is what you download. The mix renders exactly as it previews, named with the mix name and total length.
Duplicate a mix for free. Make another version of any mix and shape it differently. Credits apply only when a new song joins.
Swapping songs is free. A transition you’ve paid for stays paid. Take a song out and drop another in its place without paying again.

Your song list stays organized as it grows. Recent songs up front, search when the list gets long, and one-click access to everything older.
See how much each cut removes. Every removed section shows its length right on the bar, counted in 8-counts.
Follow-the-playhead. The view scrolls to keep your place as the song plays.
Metronome. A click track on the beat while you work.
A guard against choppy cuts. If a cut is so short it might sound choppy, Smart678 says so before you download and offers to clean it up.
Zoom in and out. Fine detail for precise work, or the whole song at a glance.

Studio-ready downloads. MP3 at 320 kbps or WAV at 44.1 kHz / 16-bit, named with your routine’s length.

Simple credits. One credit unlocks one song, with unlimited revisions and downloads of it forever.
Never charged twice for the same song. Re-uploading a file you already brought in is free.

Your first 5 song edits are free.