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changing tempo with real instruments in garageband
Old 1 week ago
  #1
Here for the gear
 

changing tempo with real instruments in garageband

hi folks - just finished a song using real instruments in garageband and now realise that its too slow. short of re-recording the whole thing, surely there's a way to automate this? I'm looking at jumping the whole thing up by only about 6-8bpm.

When i change the master tempo track it only changes midi tracks and the click tempo but leaves the real instrument tracks (recorded through a mic)

any help much appreciated
Old 1 week ago
  #2
Gear Maniac
 

What is the current BPM? I have never changed tempo on recorded material, but I guess +6-8 BPM would affect sound quality more if the base tempo is 60 compared to 160.

It’s less straightforward in GarageBand but I think there’s a guide here:
https://discussions.apple.com/thread/8344409

In Logic you just drag and stretch
Old 1 week ago
  #3
Here for the gear
 

thanks. enabling flex and selecting 'follow tempo' is working. cant vouch for its quality yet... tempo is currently 67bpm. adjustment might even be less that 6-8bpm. and it affected the integrity then i'd opt to re-record.
Old 1 week ago
  #4
Quote:
When i change the master tempo track it only changes midi tracks and the click tempo but leaves the real instrument tracks (recorded through a mic)
That is because only MIDI follows project tempo. Audio never follows project tempo, as audio is recorded and played back at the tempo it is recorded at. so changing the tempo for the project will never change the audio tempo, just the MIDI tempo, as MIDI follows project tempo, unlike audio.

I have and use programs audio snap that can change the tempo of audio perfectly from going from 60 to 90bpm or 100 to 130 bpm.
Old 1 week ago
  #5
Lives for gear
 

Back in the day you used to speed a recording up by varying the speed of the tape. Its didn't just change the tempo however it also changed the pitch.
Many notable songs had the recording speed up to put a little snap in the tempo and make their voices sound more feminine.

If this is a non midi recording most DAW programs have a stock tool which will allow you to time/pitch stretch. The cool part about digital is you can change pitch without affecting tempo or change tempo without affecting pitch. How well des it work? I'll let you judge. I've tried it within a number of DAW programs and editors and the music becomes more glitchy to my ears, especially for songs that have allot of clutter (background white noise from distorted instruments and cymbal wash) to begin with. I'd suggest not speeding it up more then 10~20% max but again that will vary on the music and recording quality.

Played back to back with the original you'll likely find the original has superior fidelity so the real answer to your question is, yes if you want a faster recording, you need to redo the whole thing, but that's no guarantee the song will be played as well. It may come out better or worse depending on how well you're playing that day. maybe you want to keep this lesson in mind next time you record and do the first backing tracks at a couple of different speeds in case you need a different tempo song. I often do this when writing music. I may do the song with different beats and different tempo's. Cant tell you how many times the version I thought the least of wound up being the real keeper. You simply cant always judge music when tracking and it can sound quite different when mixing.

As far as garage band having that tool, I'm not sure, you'll have to check. The only version I have of the program is on my iPhone and I run PC's not Macs.
What I'd suggest is it doesn't is download a free audio editor program instead of buying a whole new DAW program. Most editors can be used for mastering mixdowns so its simply finding one with Time/Pitch stretching.

I know my old versions of Cool Edit, Wavelab and Sound Forge can all tempo stretch/shrink a song. You basically export the song as a stereo recording then open it up in the editor and can time compress it there. I still use an audio editor for all my mastering work. It forces me to wear a different hat and take the recording to a higher level. I apply all may master EQing, Multi Band limiting and Brick wall limiting. The editors I use allow me to use any of the VST plugins I use in the DAW. The big benefit is you see and use RMS levels instead of peak levels so you can actually see how loud the file is by comparing the size of the waveform to the screen and the grids are 2dB each so I can tweak a recording up to commercial levels quite accurately simply doing it visually.

Again, I'm not a Mac guy so I'm not sure what editors will work for you but if you don't have one that's right where I'd go first. You can simply Google Free Audio editor and come up with a dozen or more to try. Then if you find one that you like in demo version you can spring for a few bucks to buy the full feature version.
I'm not sure why nobody on this site talks about the benefits of having a good editor but I suppose I got used to it early. I used to record to tape then when the first CD burners came out around 1996 or so I started mixing down and recording onto the computer through the sound card computer, Mastering the mixes then burning my own CD's. I actually learned to master digitally before I got my first Multi channel audio interface. anyway give it a shot. Maybe you'll get lucky and the loss in fidelity wont be too bad compared to the benefits.
Old 1 week ago
  #6
Gear Guru
 

Quote:
Originally Posted by moongod View Post
hi folks - just finished a song using real instruments in garageband and now realise that its too slow. short of re-recording the whole thing, surely there's a way to automate this? I'm looking at jumping the whole thing up by only about 6-8bpm.

When i change the master tempo track it only changes midi tracks and the click tempo but leaves the real instrument tracks (recorded through a mic)

any help much appreciated
MIDI is just note-on and note-off data, so changing speed does not alter the sound. You will have to time-stretch the audio tracks in order to speed up or slow down your whole song. In all likelihood, this will result in unpleasant artifacts. The bigger the tempo change, the worse the sound. If it is just a small change, you might as well leave it at the original tempo. If it is a big change, the best sounding result will be to re-record all your audio instruments.
Quote:
I'm looking at jumping the whole thing up by only about 6-8bpm.
Garageband can do this. Do a search for: Time Stretching Audio Garageband and give it a try. Don't be surprised, though if the results are garbled and weird. There are third-party time and pitch softwares. But some of them are quite pricey. Once I downloaded a whole mess of them and in the demo periods, I got my task done. What I learned was that some were 'less horrible' on drums and some were marginally better on bass instruments and so on.

Last edited by joeq; 6 days ago at 01:50 AM..
Old 4 days ago
  #7
Here for the gear
 

Quote:
Originally Posted by CJ Mastering View Post
That is because only MIDI follows project tempo. Audio never follows project tempo, as audio is recorded and played back at the tempo it is recorded at. so changing the tempo for the project will never change the audio tempo, just the MIDI tempo, as MIDI follows project tempo, unlike audio.

I have and use programs audio snap that can change the tempo of audio perfectly from going from 60 to 90bpm or 100 to 130 bpm.
This depends on what DAW you use, and I'm not sure GarageBand will give you the tools for this. I know DAWs like Samplitude and maybe Pro Tools have Audio Quantize and Musical Tempo features that allow you to do this.

I doubt GarageBand has this type of tuning. You migiht actually have to use something like Melodyne, if its possible there.
Old 3 days ago
  #8
Here for the gear
 

thanks all for the advice. much appreciated.

turns out you can tempo/pitch stretch in GB but as predicted above it results in some quality loss. To my ears, even at a tiny % change. It seems the act of digitising an audio track to allow for tempo stretching does compromise the sound. For vocals this is more extreme. I'm sure there are better quality stretching solutions out there but for one song I'm reconciling myself to having to redo the whole thing.And at least to match the performance.

And a good point above about tracking at different bpms. What sounds right at that stage can change over the course of a production. I'm adding real drums towards the end of the process but in my previous experience of tracking live, the drummer has always made the best call on the tempo. Something I'll keep in mind in future - get a drummers POV on tempo before you track!
Old 2 days ago
  #9
Gear Guru
 

Quote:
Originally Posted by moongod View Post
And a good point above about tracking at different bpms. What sounds right at that stage can change over the course of a production. I'm adding real drums towards the end of the process but in my previous experience of tracking live, the drummer has always made the best call on the tempo. Something I'll keep in mind in future - get a drummers POV on tempo before you track!
I am a drummer, and I would like to think I am sensitive to initial tempos. But another thing that I have noticed happening to me is a kind of "Tempo Burn Out". That is, after starting a song and working on it for a long time, every note becomes more and more familiar - and now the same song starts to feel "slow" to me. Much like a band that has had a song in its set for many years may start to speed up that song at their shows.

I noticed that the vast majority of times that I (or any of my clients) have ended up dissatisfied with a song's tempo, it's been because we felt it was too slow. Almost never is the complaint: "we made it too fast". So, I have in recent years, set the tempos a bit faster "than I think" and usually that works out ok for me. YMMV

Quote:
It seems the act of digitising an audio track to allow for tempo stretching does compromise the sound.
Well your audio is "digitized" the minute you record it into Garage Band.

One thing that happens is that time stretching is always destructive. That is to say, if you speed it up and then slow it back down to the original speed the sound is not "back to normal" - it is twice as compromised because it has been stretched twice. Once forward and once back. If you want to try a new tempo, always revert to the original, don't "re-stretch" a stretched track.
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