What Is Crossfading in Music?

Crossfading is a technique that creates a smooth transition from one sound to another. This audio effect works like a fader but in opposite directions, meaning the first source can fade out while the second fades in, and it all mixes together.

It's often used in audio engineering to fill in the silence between two tracks or even blend multiple sounds in the same song to create smooth changes rather than abrupt ones.

DJs often make use of the crossfading effect between tracks to enhance their music performance and to make sure there aren't any sudden silent gaps that could annoy the audience or the people on the dance floor.

Crossfading is sometimes spelled cross-fading and referred to as gapless playback or overlapping songs.

Analog vs. Digital Crossfading

With the invention of digital music, it's become relatively easy to apply crossfading effects to a collection of songs without needing any special hardware or audio engineering knowledge.

It's also much simpler to do compared to crossfading using analog equipment. If you're old enough to remember analog tapes, crossfading required three cassette decks—two input sources and one for recording the mix.

Crossfading digital audio sources can also be done automatically rather than having to manually control the input levels of the sound sources in order to achieve gapless playback on the recording. In fact, when the right type of software is used, there is very little user input required to achieve professional-sounding results.

Software Used to Crossfade Digital Music

Depending on what you want to achieve, there are several types of software applications (many free) that you can use to apply crossfading to your digital music library.

The categories of audio programs that often have the facility to create crossfades include:

• DJ Mixing Software: As well as gapless playback of your music files using crossfading, DJ programs have other sound processing tools you can use such as beat matching (BPM detection), time stretching, and sample looping.
• Media Players: Many jukebox software programs like iTunes, Windows Media Player, and others come with an automatic crossfading feature that can be used not only for music files but also for your playlists too. For ease of use, software media players are probably as simple as it gets.
• CD Burning Software: Some DVD/CD burning software can be used to burn digital audio files to audio CDs that have crossfading. This is a type of virtual crossfading that's added to the music during the burning session. The process doesn't alter any of your original files, so they remain unchanged on your computer's hard drive.
• Online Music Services: Some online music services provide free application downloads that can crossfade streaming audio using extra buffering. Spotify is one example that provides this facility in both its desktop and mobile software.
• Audio Editors: Audio editing software such as the free Audacity program can be used to create new mixes that have crossfaded tracks. This type of software is a bit different from the other examples above (excluding audio CD burning)—you're actually creating a new digital audio file, rather than just adding a non-permanent effect.