sampling related theory questions

daniel9321

New member
Basically, I'm a total beginner when it comes to sampling and production in general. I have seen a few tutorials and in one of them someone mentioned that the length of the sample should be dependent on the tempo of the sample. Is this true and if so what does this mean? Also, when laying down the sample chops on the piano roll, does it matter how many bars the pattern is before looping? I don't know if that makes sense but basically what I mean is, does it matter if the pattern loops after 1 bar or 3 or 4 for example? I don't know if I'm just overthinking it all but when I've been trying things out, it doesn't seem to sound that great.
Any tips in general would be great. Thanks (also I'm using FL Studio if that helps).
 
tempo is a statement of how many beats per minute

120bpm means 2 beats every second so 4 bars of 4/4 will be 8 seconds long

a sample/project will usually have a sample rate: 44.1kHz/48kHz

A problem you will encounter is that we use the word sample for two different yet related aspects.

The first is the actual piece of music you are going to use: the whole of the segment is a sampling of the entire piece it comes from

When chopping a sample you want to be certain of the tempo the sample is playing at. Unfortunately unless it is sequenced there is a good chance that the tempo will change every beat as human beings do not play with perfect timing. Even with great players there will still be some wiggle room on timing and the beat may nudge up and down a few bpm all the way through.

The second is the individual slice corresponding to 1 step of the sample rate

44.1khz means that 1 sample step = 1/44100 seconds (0.022676 milliseconds) or more concisely 1 second = 44100 samples

48kHz means that 1 sample step = 1/48000 seconds (0.020833 milliseconds)
 
When you change the pitch up or down on a sample, it will become shorter or longer in order to preserve sound quality. Picture somebody playing a record at a fast or slow tempo, it will be higher pitched when played fast and lower pitched when played slow. The same thing applies to sampling on your computer. You can adjust the speed/length of the sample and the pitch independently but you'll be losing sound quality every time you adjust one without the other following it. Does that make sense?

Also, it doesnk't matter what the bars are for your sample, there's no set rules. Just try to keep it in time with the metronome on FL Studio. If you're sampling a 4 bar piece of a song, then you could make it be 4 bars in FL Studio or perhaps 2 bars and pitch it up. It's all up to you, just try to keep it in time with your drums and the FL metronome!
 
When you change the pitch up or down on a sample, it will become shorter or longer in order to preserve sound quality.

this is only true if you use the record-player/tape machine method of pitch shifting (a 33rpm played at 45RPM or a 45 RPM played at 78RPM and vice versa for record player and then you have tape machines that can change pitch by playing the tape faster or slower - it is the key to how the Alvin and Chipmunks were first recorded; later tape machines also had a small variable speed control, usually +/- 15% )

you can also pitch shift without changing the duration/length, known as a pitch domain convolution

you can also do a time shift without changing the pitch (the infamous slow down and practice method of the early Boss/Roland disk recording systems), this is known as a time domain convolution

the first one does not introduce any noticeable artefacts as every thing is maintained in the same relationships

the other two tend to create artefacts the more pronounced the change: pitch shifting by a second up or down is usually no problem, time-shifting by about +/- 15% is also no problem)
 
bandcoach, you seem to know you're stuff! a lot of it's going over my head atm lol but do you know any good resources for beginners who want to widen their knowledge? how did you get to where you are in terms of understanding?
 
lots of reading, lots of practical application and even writing my own code to do the above processes using pascal on an atariSt

get a hold of "the computer music tutorial" by Curtis Roads (it's 19 years old but still relevant today) for a good all round presentation on the the processes and the math behind what happens in synthesis and and other dsp related aspects of making music with computers

if you are mad keen on understanding the maths behind it all the following may be of interest:

http://www.musicdsp.org/archive.php?classid=0

The DFT “à Pied”: Mastering The Fourier Transform in One Day : The DSP Dimension

Pitch Shifting Using The Fourier Transform : The DSP Dimension

Fast Fourier Transform Source code in Visual Basic - FFT

fft - (tutorials) - dsp fft fast fourier transformations

COMP449: Speech Recognition

Chapter 5. Time Domain Processing

Chapter 6. Frequency Domain Analysis

Bores Signal Processing - Introduction to DSP - index

SpectroType Tone Generator - The Aphex Face with Text!

https://ccrma.stanford.edu/~jos/mdft/

Tech Stuff - Equalization (EQ), Metering and the FFT

Music and mathematics - Wikipedia, the free encyclopedia

some of the above includes code you could use to create your own plugins and in some cases plugins are already available as well
 
I did but you did not put limits on the extent to which you can do it without the artefacts taking over - that is all I added to your explanation that and the technical names for what each type of shifting is known as .....
 
To the OP...

youtube has sampling tutorials for pretty much every system/daw just search 'sampling tutorial' with whatever you're using eg: 'FL Studio sampling tutorial' or 'MPC1000 sampling tutorial' or 'maschine sampli....' etc etc...
 
Back
Top