Accidentals: Sharps, Flats, Naturals
Accidentals temporarily change a note’s pitch. On guitar, that usually means moving the same note one fret higher (sharp) or one fret lower (flat), while staying on the same string unless you choose an alternate fingering.
Sharp (♯)
A sharp raises a note by one semitone (one fret). Example: F becomes F♯.
- On the 1st string: F (1st fret) → F♯ (2nd fret)
- On the 6th string: F (1st fret) → F♯ (2nd fret)
Flat (♭)
A flat lowers a note by one semitone (one fret). Example: B becomes B♭.
- On the 5th string: B (2nd fret) → B♭ (1st fret)
- On the 2nd string: B (open) → B♭ (1st fret)
Natural (♮)
A natural cancels a sharp or flat and returns the note to its “plain” form (the pitch implied by the key signature or by no accidental). Example: if F♯ is in effect, then F♮ means play F natural.
- On the 1st string: F♯ (2nd fret) → F♮ (1st fret)
The Measure Rule: How Long Accidentals Last
An accidental affects the same note name (same letter) for the rest of the measure, in the same octave, unless canceled by another accidental. At the barline, the effect ends (key signature still applies, but “one-time” accidentals do not carry over).
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What “same note name” means on guitar
If a measure contains an F♯, then any later F in that same measure (in the same octave on the staff) is also F♯, even if the sharp sign is not repeated. This is a reading rule, not a fingering rule: you may play that F♯ on different strings if you know alternate locations, but in first position you’ll usually stay with the simplest option.
Mini-examples (reading logic)
| Situation | What you do |
|---|---|
| Measure shows F♯ once, then later another F (no sign) | Play F♯ again (still in effect) |
| Measure shows B♭, then later B♮ | First B is flat, later B is natural (natural cancels) |
| New measure starts after an accidental | Accidental from previous measure no longer applies (unless the key signature says otherwise) |
Key Signatures: Accidentals That Apply All the Time
A key signature is a set of sharps or flats placed at the beginning of each staff line. Unlike a one-time accidental, a key signature applies to every occurrence of those note letters throughout the piece (every measure), unless a natural (or other accidental) temporarily overrides it.
In first-position reading, you can get a lot of mileage from three common key signatures:
- C major / A minor: no sharps or flats
- G major / E minor: 1 sharp (F♯)
- F major / D minor: 1 flat (B♭)
Key signature quick recognition
- One sharp: it is always F♯ (in these early keys). You should immediately expect every written F to be played as F♯ unless marked natural.
- One flat: it is always B♭. You should immediately expect every written B to be played as B♭ unless marked natural.
First-Position Locations for the Altered Notes (F♯ and B♭)
Before drilling, lock in the most common first-position fingerings for the altered notes you’ll see in these keys.
F♯ in first position
- 1st string, 2nd fret: F♯ (often the easiest when you see F on the top space/line area)
- 6th string, 2nd fret: F♯ (useful for bass patterns)
- 4th string, 4th fret: also F♯, but this is outside strict first position; avoid for now unless instructed
B♭ in first position
- 5th string, 1st fret: B♭ (common in bass lines)
- 2nd string, 1st fret: B♭ (common in melody lines)
Step-by-Step: How to Read a Measure with Accidentals or a Key Signature
Step 1: Name the key signature out loud
Examples: “No sharps or flats.” / “One sharp: F-sharp.” / “One flat: B-flat.”
Step 2: Predict the altered letters before you play
Say: “All F’s are F♯” or “All B’s are B♭.” This is your first “spot check” habit.
Step 3: Scan the measure for naturals or extra accidentals
Look specifically for ♮, ♯, ♭ signs inside the measure. These override the key signature temporarily.
Step 4: Apply the measure rule
If you see an accidental on a note, keep it in effect for the rest of that measure for that same note name (same octave on the staff), unless canceled.
Step 5: Choose the simplest first-position location
When you see F♯ or B♭, default to the first-position options listed above unless the musical context clearly requires another string (for example, to avoid a big jump).
Targeted Drill 1: Identify Altered Notes on the Staff (No Guitar Yet)
For each line, do two things: (1) say the key signature, (2) list which written notes will be altered.
Drill A: C major / A minor (no accidentals)
- Spot check: “No sharps, no flats. Nothing is altered unless I see an accidental.”
- Now look at a measure you’re practicing: circle any ♯/♭/♮ you see and say what they do.
Drill B: G major / E minor (one sharp)
- Spot check: “One sharp: F♯. Every F is sharp unless natural.”
- On a printed exercise, highlight every written F. Say “F-sharp” for each one before playing.
Drill C: F major / D minor (one flat)
- Spot check: “One flat: B♭. Every B is flat unless natural.”
- On a printed exercise, highlight every written B. Say “B-flat” for each one before playing.
Targeted Drill 2: Locate the Altered Notes in First Position
Use this as a rapid-response drill. Set a slow tempo and answer within one beat.
Flash prompts (say it, then place the finger)
- “F♯ (melody)” → 1st string, 2nd fret
- “F♯ (bass)” → 6th string, 2nd fret
- “B♭ (bass)” → 5th string, 1st fret
- “B♭ (melody)” → 2nd string, 1st fret
- “F natural (cancel F♯)” → 1st string, 1st fret (after saying “natural cancels”)
- “B natural (cancel B♭)” → 5th string, 2nd fret or 2nd string open (choose the one that fits the line you’re reading)
Targeted Drill 3: Short Playing Patterns That Highlight the Key Signature
Play these patterns slowly and evenly. The goal is not speed; it’s automatic recognition of the altered note.
Pattern Set 1: G major / E minor (F♯)
Spot check before playing: say “One sharp: F-sharp. All F are F-sharp.”
Pattern 1 (melody focus, 1st string): E F♯ G F♯ E D E F♯ G (repeat) Pattern 2 (bass focus, 6th string): E F♯ G F♯ E (repeat)Self-check questions while playing: “Did I ever play F natural by mistake?” “Did I hesitate when I saw an F?”
Pattern Set 2: F major / D minor (B♭)
Spot check before playing: say “One flat: B-flat. All B are B-flat.”
Pattern 1 (bass focus, 5th string): A B♭ C B♭ A G A B♭ C (repeat) Pattern 2 (melody focus, 2nd string area): A B♭ C B♭ A (repeat)Self-check questions while playing: “Did I accidentally play B natural?” “Did I remember B♭ without seeing a flat sign on every B?”
Pattern Set 3: Naturals that override the key signature
These patterns train you to notice a natural sign and immediately cancel the key signature for that note.
In G major (F♯ in key signature): E F♯ G F♮ E F♯ (repeat) In F major (B♭ in key signature): A B♭ C B♮ A B♭ (repeat)Rule reminder: the natural applies through the measure (for that note name in that octave), then the key signature returns in the next measure.
Spot Checks (Verbalize, Predict, Then Play)
Use these as a quick routine before any new line of music. Do not skip the speaking step; it builds the reflex that prevents wrong notes.
Spot Check 1: Identify the key signature
- If you see no sharps/flats: say “C major / A minor: none.”
- If you see one sharp: say “G major / E minor: F-sharp.”
- If you see one flat: say “F major / D minor: B-flat.”
Spot Check 2: Predict the altered notes
- One sharp: “All F are F-sharp.”
- One flat: “All B are B-flat.”
Spot Check 3: Scan for exceptions in the measure
- Say: “Any naturals? Any extra sharps or flats?”
- If you find one, point to it and say what it changes (example: “F natural cancels F-sharp for the rest of this measure”).
Spot Check 4: Play only the affected notes first
Before playing the full measure, play just the notes that are altered by the key signature (all F’s or all B’s) in rhythm, then play the full measure. This isolates the most common reading mistake.
