How Beat Mixing works
Using Snap To Beat
The "tempo" of a track refers to how fast or slow it is. Tempo affects the mood of a piece—a fast tempo makes music feel exciting or energetic, while a slow tempo feels more relaxed.
One way tempo can be measured is in "beats per minute," or BPM. Most dance music ranges between 110 and 140 BPM. A mellower track would have a lower BPM, while a high-energy sound would have a higher BPM. In most dance music, you can hear the thumping sound of the kick drum on each beat.
To do Beat Mixing, the speed—or BPM—of one or both tracks needs to change so that they have the same BPM at the point where they overlap. In the illustration which follows, notice how the spikes (or beats) of the upper track line up with the spikes of the lower track. Because the beats of the two tracks are coordinated, the transition between tracks is hard to detect. When RecordForAll changes the BPM of a track, however, it changes only the tempo; it doesn't distort the sound of the voices or the instruments.
Keep in mind that for most of a track's duration, it will retain its original BPM. But RecordForAll prepares for the overlap of two tracks by gradually slowing down or speeding up a track to meet at an intermediate BPM for the duration of the overlap. When you turn on Beat Mixing, RecordForAll uses this technique to link tracks together. (You can then fine-tune this automatic Beat Mixing however you like.)
For example, let's say track A has a BPM of 130 and track B has a BPM of 140. The BPM at their overlap will be about 135. About 30 seconds before the overlap, track A will start to speed up gradually so it reaches 135 when it overlaps with track B. Once track A has stopped, track B will take about 30 seconds to speed up to its normal BPM of 140.
When you enable Beat Mixing, RecordForAll defines an eight-measure Intro Range and an eight-measure Outro Range for each track. It then lines up the sprockets for the Outro Range of the outgoing track with the Intro Sprockets for the incoming track. During the time when the Outro and the Intro overlap, RecordForAll lines up the beats of the two tracks, adjusting the tempo of both tracks so that it is between the tempos of each of the tracks. The tempo change occurs gradually to make the transition smooth; it doesn't affect the original pitch of the music. The gray tempo boxes at the bottom of the Timeline show the precise changes that RecordForAll makes to the tempo over time.
RecordForAll creates an 8-measure (Short Beat Mix) or 16-measure (Long Beat Mix) Intro Range and Outro Range at the beginning and end of each track. In most dance music, a measure is four beats.
If you're not familiar with musical terminology, think of the parts of a track as a poem. Each beat is like a syllable. Each measure is made up of four beats (usually) and forms a word. A phrase is made up of multiple measures (typically 8) and forms a musical sentence. Most great beat mixes line up the phrase from one track with the phrase from another track. In the process it fades from one to the other. The result is a smooth "morphing" from one track to another.
RecordForAll then takes these ranges (Intro and Outro) and stretches each track. It makes the measures in the Outro Range from the first track the same length as the measures in the Intro Range of the second track. It does this by changing the tempo of one or both tracks. RecordForAll also cross-fades the volume during the time both tracks play. These default settings created by RecordForAll give you the makings of a great mix.
Beat Mixing works best with tracks that have a similar beat, such as those considered "dance" tracks. For tracks with dissimilar tempos, Crossfade Mixing is best.