What is SFZ?

This is the main reference point for anyone who wants to create virtual musical instruments using the SFZ format. Currently the SFZ 2 opcodes and ARIA extensions are documented though some require more detail, and SFZ 2 opcodes not supported by ARIA still need to be added. There's enough information to make complex SFZ instruments already, but we'll continue to add more.

To make use of the SFZ format requires three things:

which tells the player how to use the samples. The SFZ file itself can be created using any text editor, though for more complex cases with hundreds or thousands of samples, additional tools can make this easier - some people use spreadsheets, and there are also dedicated SFZ creation tools.

The SFZ format is a file format to define how a collection of samples are arranged for performance. The goal behind the SFZ format is to provide a free, simple, minimalistic and expandable format to arrange, distribute and use audio samples with the highest possible quality and the highest possible performance flexibility. Soundware, software and hardware developers can create, use and distribute the SFZ format files for free, for either free or commercial applications.

Here's a basic SFZ file you can copy to start your own
Here is the list of SFZ headers
The list of SFZ 1 opcodes can be found here.
You can browse the many SFZ 2 opcodes starting here.
A few opcodes have been added to ARIA / Sforzando for more flexibility

What SFZ is not

To clarify, the term SFZ as used on this site does not mean a sforzando dynamic marking, and it also is not the same thing as a soundfont. Soundfonts are a completely different file format which includes both the samples and the definitions of sample behavior in the same binary file, while SFZ is a file format which only defines the behavior of musical instruments and does not include the sample content. SF2 may look a bit like SFZ visually, but that's a coincidence.

Making Instruments

Text guides on how to make a simple instrument, covering the essential opcodes

Drum basics - covers global, group and region headers, sample, key, lovel / hivel, amp_velcurve_N, seq_length, seq_position and lorand / hirand.
Sustained note basics - using a flute as an example. Adds lokey / hikey, pitch_keycenter, xfin / xfout, locc / hicc, keyswitching, group, off_by and off_mode.

Some more advanced topics

Vibrato - typical string vibrato, humanized vibrato, asymmetrical vibrato, and even filter wobble.
Legato - simulated legato and portamento as well as true sampled legato.
Cymbal muting - using group, off_by, off_mode and polyphony to make hi-hat and cymbal notes mute previous notes in a musically useful way.
Brush stirs - two different approaches to brushed drum techniques which produce a continuous sound rather than a hit.