Bass Notes Piano Chart: Find Lower Notes on an 88-Key Keyboard
The lowest key on a standard 88-key piano is A0, while middle C is C4. A bass-note chart is useful when it connects a written or named note with the correct keyboard octave, rather than giving a letter without its register.
The table below covers the lower keyboard through middle C. “Bass” here describes a useful learning region, not a rule that every note must be played by the left hand.
Lower-keyboard chart
| Piano key number | Note | Approximate Hz |
|---|---|---|
| 1 | A0 | 27.50 |
| 2 | A♯0/B♭0 | 29.14 |
| 3 | B0 | 30.87 |
| 4 | C1 | 32.70 |
| 5 | C♯1/D♭1 | 34.65 |
| 6 | D1 | 36.71 |
| 7 | D♯1/E♭1 | 38.89 |
| 8 | E1 | 41.20 |
| 9 | F1 | 43.65 |
| 10 | F♯1/G♭1 | 46.25 |
| 11 | G1 | 49.00 |
| 12 | G♯1/A♭1 | 51.91 |
| 13 | A1 | 55.00 |
| 14 | A♯1/B♭1 | 58.27 |
| 15 | B1 | 61.74 |
| 16 | C2 | 65.41 |
| 17 | C♯2/D♭2 | 69.30 |
| 18 | D2 | 73.42 |
| 19 | D♯2/E♭2 | 77.78 |
| 20 | E2 | 82.41 |
| 21 | F2 | 87.31 |
| 22 | F♯2/G♭2 | 92.50 |
| 23 | G2 | 98.00 |
| 24 | G♯2/A♭2 | 103.83 |
| 25 | A2 | 110.00 |
| 26 | A♯2/B♭2 | 116.54 |
| 27 | B2 | 123.47 |
| 28 | C3 | 130.81 |
| 29 | C♯3/D♭3 | 138.59 |
| 30 | D3 | 146.83 |
| 31 | D♯3/E♭3 | 155.56 |
| 32 | E3 | 164.81 |
| 33 | F3 | 174.61 |
| 34 | F♯3/G♭3 | 185.00 |
| 35 | G3 | 196.00 |
| 36 | G♯3/A♭3 | 207.65 |
| 37 | A3 | 220.00 |
| 38 | A♯3/B♭3 | 233.08 |
| 39 | B3 | 246.94 |
| 40 | C4 | 261.63 |
Sharp/flat alternatives identify the same physical key in ordinary equal-tempered tuning. Their spelling in a score still matters; the table does not erase harmonic context.
Use the black-key groups as landmarks
The white key immediately before a group of two black keys is C. The white key immediately before a group of three is F.
Once you identify a letter, locate the correct octave. C2, C3 and C4 share a letter but occupy different regions. Adjacent Cs are one octave apart, with a two-to-one nominal frequency ratio.
The lowest part of the keyboard starts with A0 and B0 before the first C1. Do not assume that every piano begins on C.
Connect the keyboard to bass clef
The ordinary bass staff has G2 B2 D3 F3 A3 on its lines and A2 C3 E3 G3 in its spaces, counted from bottom to top.
Middle C4 sits on the first ledger line above that staff. E2 sits on the first ledger line below; lower notes need additional ledger lines or another appropriate notation instruction.
The bass-clef staff chart explains each position. Use it when the difficulty is reading notation rather than locating the key physically.
Read an accidental before pressing the key
A staff position gives the letter and octave. The key signature and local accidental determine whether it stays natural or changes.
For example, a written F3 with a sharp requires F♯3 rather than the natural F3 key. The black-key pattern helps locate the result, but it does not replace reading the score.
There is no black key between E and F or B and C. That keyboard fact is important when counting semitones or finding the neighbouring target.
Begin with a small pattern
Find C3, then D3 and E3. Name them, play an easy rhythm and compare their direction by ear. Add the surrounding notes only after the small task is clear.
Next try C3 to G3 and back. Identify the endpoint keys before moving, then work on a manageable hand movement with suitable fingering guidance.
Do not force an octave stretch or a fixed finger assignment to match a generic chart. A note map identifies pitch locations, not a universal hand shape.
Chord tones and bass movement
A simple C-major chord uses the pitch classes C, E and G. A low C bass note and an upper C-major chord can support the same harmony without placing every chord tone in the lowest octave.
Low dense voicings can sound different from more widely spaced ones. The note chart supplies positions; arrangement and listening determine how to use them.
The scale guide explains note collections, while the key guide separates a tonal framework from one low note.
Why frequency values are references
The table uses twelve-tone equal temperament with A4 = 440 Hz. An acoustic piano’s actual tuning can include stretch related to its string behaviour, so the numbers are not a complete prescribed tuning curve.
A measured partial also need not equal the fundamental listed in the table. Listen and use a source-appropriate method when investigating a recording.
The piano-analysis guide explains why consumer readings do not replace professional instrument service.
Using a detector with low piano notes
Check its minimum frequency. This site’s current main/file pitch search starts at 50 Hz; A0, B0 and several other low targets lie below that limit.
An octave-higher result may be a harmonic, not proof that the key is physically a different note. Confirm the expected register before interpreting a number.
Increasing microphone gain does not extend the configured search floor. A piano key’s known label and an estimator’s accepted candidate are different kinds of information.
Frequently asked questions
Is middle C the lowest bass note?
No. It is a useful central reference. A standard piano extends down to A0, and bass-clef notation can represent many notes below middle C.
Does bass clef always mean left hand?
No. It defines staff interpretation. Hand assignment depends on the score, and hands can cross or change register.
Why do two apps label the same key differently?
Some use different octave-number conventions. Compare frequency or MIDI identity and the application’s naming system before assuming the piano changed pitch.
Can this chart tell me how to tune the instrument?
It supplies calculated references and note locations. It is not a mechanical tuning procedure or a diagnosis of an acoustic piano.
Reference basis: standard 88-key layout, bass-clef notation and equal-tempered calculations at A440. All table values are reference calculations.