Sample tempo
Every sample on a deck can know its tempo and where its beats fall. ScratchCraft uses this to draw a beat grid on the waveform, to snap markers to beats, and for Sync Loop’s Sample mode, which plays the sample at the song’s tempo.
The BPM pill
Section titled “The BPM pill”The BPM pill sits under the Torque knob on the deck strip and shows the sample’s tempo.
- A value marked with ~ is a guess: ScratchCraft worked it out but you haven’t confirmed it.
- A value without ~ is one you set, or one remembered from before.
Click the pill for the tempo menu. Double-click it to type a BPM straight away (Enter to set, Esc to cancel).
Detection and guesses
Section titled “Detection and guesses”When you load a new sample, ScratchCraft analyses it in the background and detects its tempo and first beat. A detected tempo is still marked ~ until you confirm or change it. The menu’s header says how sure the detection is, for example “detected, confidence high”.
If detection isn’t confident, ScratchCraft falls back to a guess from the cue to the end: it assumes that stretch is a whole number of beats (1, 2, 4, 8 and so on) and picks the count whose tempo lies between 70 and 180 BPM and is closest to the song tempo.
Guesses are never stored. To keep a tempo, confirm it: type it, tap it, or use any of the menu items below.
The tempo menu
Section titled “The tempo menu”| Item | What it does |
|---|---|
| Sync this deck | Finds a good loop, sets the cue and end and turns Sync Loop on. See Sync Loop. |
| Undo sync | Puts back what Sync this deck (or a picked loop) changed. |
| Loops | Lists the best loop suggestions. |
| Type BPM… | Type the tempo. |
| Tap tempo… | Opens a tap panel (below). |
| Double (x2) / Halve (/2) | Fixes a tempo detected at half or double speed. |
| Set transport to … BPM | Standalone app only: sets the transport tempo to this sample’s tempo. |
| Cue to end is | Pick how many beats lie between the cue and end (1 to 64). Sets the tempo from that and starts the beat grid at the cue. |
| Guess from cue to end | Makes a fresh guess from the cue and end, as described above. |
| Beat grid starts at the cue | Moves the beat grid so a beat falls on the cue. |
| Clear tempo | Forgets the tempo. |
Tap tempo
Section titled “Tap tempo”Tap tempo… opens a small panel. Click Tap (or press Space) in time with the sample. The last 8 taps are averaged, and a pause of two seconds starts over. Click Use to set the deck sample’s tempo to the tapped value.
Cue to end
Section titled “Cue to end”Cue to end is is the quickest way to set an exact tempo for a loop: set the cue on the loop’s first beat and the end on the beat after its last, then pick the number of beats in between. It also puts the first beat of the grid on the cue.
The beat grid
Section titled “The beat grid”Once a sample has a tempo, the waveform draws its beat grid: bar lines brighter, beat lines dim. When you zoom out, the lines thin out to bars and then every 2, 4 or more bars, so they never crowd together.
The grid starts at the sample’s first beat. Detection puts it on the strongest low hit of a bar; Beat grid starts at the cue moves it to the cue.
The cue and end markers snap to the grid’s beats when you drag them near one. See Waveform and markers.
The pad inspector shows the grid of the sample it is showing.
The tempo follows the sample
Section titled “The tempo follows the sample”The tempo and beat grid belong to the sample, not to the deck or the project. ScratchCraft recognises a sample by its audio, so the same audio has the same tempo whether it comes from a file, a copy embedded in a project or a library save.
- Tempos are kept in
Documents\ScratchCraft\SampleInfo.xml, shared by every project and plugin instance. Set a sample’s tempo once and it is there in every project that uses it. - The project also saves the tempo of each deck’s sample, so a project opened on another computer still has its tempos.
The sample library shows a sample’s tempo in its list once it has one.