Slow 120 BPM to 90 BPM without changing the key

Tempo and pitch are separate controls, so you can make a difficult passage easier to practice while keeping it in a comfortable register. A speed of 0.75× spreads the same musical events over more time. Keeping pitch at 0 asks the processor to preserve note height. A pitch change of −2 semitones lowers every note by a whole tone while speed 1× keeps the original duration.

Use speed for more time between notes and pitch for a different singing or playing range. The processor shifts the recording as a whole, preserving the relationships between its notes. Check the source key separately when planning a transposition; moving a major-key recording up or down keeps those major-key relationships.

Use target BPM ÷ original BPM = speed. For 90 ÷ 120, choose 0.75×; for 100 ÷ 80, choose 1.25×. Output duration is selected duration ÷ speed. This relationship assumes a steady source tempo. A recording with expressive tempo changes keeps those variations after a uniform speed change, so follow its phrasing when practicing.

Tunenoodle currently offers 0.5×–2× speed and integer pitch changes from −12 to +12 semitones. Defaults are 1× and 0. One octave is 12 semitones. Lowering D major to C major uses −2; raising C major to D major uses +2. Confirm the starting key by ear or with a separate analysis before applying that example.

Suppose the difficult passage runs from 00:36 to 01:00 in a steady 120 BPM recording. Enter start 36 and end 60, speed 0.75×, pitch 0. The selected 24 seconds becomes 32 seconds. You can use the same calculation for any selected passage: subtract start from end, then divide by the speed multiplier.

If the same accompaniment is two semitones too high for your voice, set pitch to −2 while retaining 0.75×. The target duration stays 32 seconds. Process both changes from the original in one pass, then name the file with the speed and pitch so you can distinguish it from your performance-speed version.

1. Choose a browser-decodable audio file up to 20 MiB, 5 minutes and two channels. MP3, WAV and other listed extensions still depend on your browser decoding the actual file.
2. Set the start and end of the phrase. Keep the first attack and the final release; cutting exactly into a note can create a distracting boundary. Leave fades at 0 initially, or add a short fade only where needed.
3. Set speed and pitch, then run processing. Changing a setting clears the previous result, so process again before judging the new setting.
4. Compare the original excerpt and the processed result. Use looping for repetition, then download the processed WAV. Local processing does not require uploading this practice file to the cloud.

Time stretching rearranges short sections of a signal. Sustained notes and sharp attacks behave differently during that process, so audition both: a held vocal or string note shows steadiness, while drum hits and piano onsets show rhythmic definition. Compare a smooth passage and a busy passage at similar volume to choose a speed that supports the skill you are practicing.

If flutter, doubled attacks or a smeared onset becomes distracting, move the speed closer to 1× and process again from the original. You can then practice in smaller tempo steps as the phrase becomes familiar. Large pitch shifts can change vocal character; compare nearby semitone settings to find a useful range. The editor offers a pitch control without a separate formant-preservation setting.

Reopen the downloaded WAV and confirm the passage starts where expected, the ending is complete and the duration is approximately the calculated value. Check that pitch stayed unchanged when that was the goal. WAV is useful for retaining the processed result without an additional lossy encoding step; its starting detail still comes from the source recording.

Can I enter 90 BPM directly? This editor uses a speed multiplier; calculate it from the source tempo.

Which format does this editor export? The processed download is WAV. Keep a clear filename such as “phrase-90bpm-pitch0.wav” and return to the original when making your next practice version.