How to Analyze Your Whole Sample Library for Key and BPM
Most producers have a sample library problem: too many samples, not enough information about them. If you can't tell what key or BPM a sample is in without auditioning it, building beats becomes a slow process of trial and error.
Here's how to fix that systematically.
Why an Untagged Library Is a Slow Library
An unlabeled sample requires you to preview it, try to match it with what you're building, figure out the key by ear or trial and error, and potentially pitch-shift it before you even know if it works.
A labeled library flips this. When every sample has its key, Camelot code, and BPM in the filename or metadata, you filter and search by those values. Building a beat becomes: "I need a loop in `8A` around 90 BPM" → search → audition a few pre-qualified candidates → done.
Step 1: Audit What You Have
Sort your library by folder and count: - Loops and full recordings (need key + BPM analysis) - One-shots, hits, and percussion without pitch (no key analysis needed) - Pre-tagged samples from the pack (already have key/BPM)
Focus analysis time on melodic and harmonic content: bass loops, chord loops, melody loops, vocal samples, 808 samples.
Step 2: Set Up a Tagging System
Filename tagging (simplest): Rename files to include key and BPM. Example: `piano_loop_01.wav` → `piano_loop_01_Amin_8A_95bpm.wav`.
Metadata tagging: Write key and BPM into the file's metadata fields using a tool like Mp3tag, Rekordbox, or Serato. Lets software filter and sort directly.
Both: Embed in metadata AND include in filename for maximum portability.
Step 3: Analyze in Batches
Don't try to do your entire library in one session.
Batch by genre or type: Start with your most-used category (e.g., chord loops or bass loops).
Batch by sample pack: Go through one pack at a time. Check pack documentation for included key information first.
Set a daily target: 50-100 samples per day is achievable. At that rate, a 5,000-sample library is tagged in 2-3 months.
Step 4: Use the Right Detection Tool
Low End Candy's Key & BPM Detector returns the key, BPM, and Camelot code for any uploaded audio file.
[→ Analyze any sample for key and BPM](https://lowendcandy.com)
For your DAW's built-in tools: these work for a first pass but verify anything ambiguous with a dedicated tool.
Step 5: Prioritize Your Core Samples First
You don't need to tag everything at once. In most libraries, you reach for 20% of your samples 80% of the time. Identify your most-used packs and tag those first.
Maintaining the Library Going Forward
Tag new samples when you download them. Don't let the backlog grow.
Check sample pack documentation first. Many packs include key information in folder names or a readme.
When you use a sample in a project, tag it if it isn't already. The samples making it into beats always stay current.
What a Tagged Library Feels Like
You start a beat with a loop. You check its code: `9A`, 90 BPM. You search for bass loops in `8A`, `10A`, or `9B` around the same BPM. Three options come up — they all work harmonically before you even play them. You pick the best one. You're building instead of troubleshooting.
[→ Start analyzing your samples — Low End Candy Key & BPM Detector](https://lowendcandy.com)