How to Make a Mashup Using Stems

A mashup puts parts of two or more songs together so they sound like one new track. Stems make that possible, because you can take the vocal from one song and the drums and bass from another.

Step 1: Pick songs that can work together

The best mashups start with a good pairing. Look for songs that share at least one of these:

• Similar tempo. Two songs within a few BPM of each other need very little stretching. Songs at half or double each other's speed also work well.
• The same or a neighboring key. This keeps the vocal melody from clashing with the chords underneath.
• Contrasting roles. A song with a strong vocal pairs nicely with a song that has a groove and a sparse top end. Two busy, vocal-heavy songs usually fight each other.

Our guide to BPM and key basics covers how to check and match both.

Step 2: Split both songs

Upload each song and let it separate into stems. Splitting takes time, so do it ahead and keep the results in your library. Then you can load them quickly when you start mixing.

Step 3: Choose a foundation and a topline

Most mashups use one song as the foundation and another as the topline.

• Foundation: the drums and bass (and often the guitar or "other" stem) from one song.
• Topline: the vocal from the second song.

Load the foundation stems onto their channels, then add the vocal. Resist the urge to use everything. Two basslines or two lead vocals at the same time make the mix muddy and confusing.

Step 4: Match tempo and key

Bring the vocal and the foundation to the same tempo. Small adjustments sound natural, and large ones start to sound robotic, especially on vocals. Then listen for key clashes. If the vocal sounds off against the chords, shift its pitch by a semitone or two, or shift the foundation instead.

Step 5: Line up the downbeats

Even at the same tempo, the two parts need to start on the same beat. Songs are built in phrases of 4, 8, or 16 bars. Start the vocal where one of its phrases begins, and line that up with the start of a phrase in the foundation. If it feels slightly early or late, nudge the stem's start point until the downbeats hit together.

Step 6: Balance and EQ

• Set the gain on each channel so no stem jumps out. Stems from different songs arrive at different loudness.
• Cut some low end from the vocal so it does not compete with the bass and kick.
• If the foundation has a prominent midrange part, make a little room by pulling that band down slightly where the vocal sits.

Step 7: Add shape

A mashup that stays the same the whole way through gets boring. Try bringing stems in and out: start with only drums, add the bass, then bring the vocal in on a chorus. Drop the drums for a breakdown, then bring them back for the final section. Even simple changes in which stems are playing give the track a sense of movement.

Common problems

• It sounds crowded. Remove a stem. Fewer parts almost always sound better.
• The vocal sounds robotic. You stretched or shifted it too far. Pick a different song, or move the other stems toward the vocal instead.
• It feels off the beat. The downbeats are misaligned by a fraction. Adjust the start point rather than the tempo.
• The vocal has a watery quality. That is a separation artifact. It is usually masked once the vocal plays with the rest of the mix.

A note on rights

A mashup is built from other people's recordings. Using it privately or for practice is one thing, but releasing or performing it publicly may require permission from the rights holders. Check the licensing before you share anything widely.

Ready to build one? Open the Stemline101 mixer.