Basically how is the pitch accuracy of a musical instrument. Does your ukulele play in tune without the notes being flat, sharp, or both if within a chord. Now a lot inexpensive ukuleles inherently will not play in tune higher up the neck, especially the shorter scale soprano. Tuning is a comprise for have melodies and chords sound good. The better the ukulele and the longer the scale length the better chance of getting it to play in tune along the entire fingerboard.

Action ia a function of the placements of the frets, the nut, bridge. and saddle as well as the height of the strings in relation to the frets when fretted or played open. The distance of the strings from the fret is referred to as the Action.

All but the fret placement can be maintained by yourself or a qualified technician, luthier, or repair person.

Pick up a String Action Gauge from Stewart-MacDonald (StewMac). StewMac is a great place for quality tools and videos for learning how to works on instruments.

StewMac: Metric String Action Gauge

Note: Even though LearningUkulele.com—(Learning Ukulele with Curt) is located in the United States — one of two countries that do not use the Metric System . I would recommend going metric for all measurements. — A lot easier when doing math with measurements.

Here are some starting measurements for Ukulele from StewMac:

• Ukulele: Action at 1st fret Bass G: .40mm, Treble A: .40mm
• Ukulele: Action at 12th fret Bass G: 2.0mm, Treble A: 2.0mm
• Ukulele: Relief at 12th fret .05mm

• Stewmac: String Action Gauge
• D'Addario: String Height Gauge
• Martin: String Action Gauge
• Philadelphia Luthier Tools: String Action Gauge METRIC Ruler - Guitar setup tool
• Philadelphia Luthier Tools: Hosco's Step Gauge for Guitar Setup Tool • This tools is multi-purpose and in addition to string actions measurements can be used for fret crown height, and nut slot depth.
• MusicNomad Equipment Care: Precision String Action Gauge (Item Number: MN602) • Include Measurements in Inches, Metric & 64ths to Customize to Your Preference.

• HOSCO: Step Gauges for Ukulele (H-SG-U) • This product page contain detailed information on using this tool as well as videos.
• HOSCO: Groobar™ -Nut Slot Assist Tool (H-GB4U) • This product page contain detailed information on using this tool as well as videos.

NOTE: I (Curt), have used all of the above tools with my own ukuleles and in our Funky Frets repair and setup shop for customers. Funky Frets sells the Martin and D'Addario tools. I have bought from both Stewmac and Philadelphia Luthier Tools and would recommend them for any of your repair and setup tools. I would recommend the metric versions and learn to use the Metric System for measuring when doing any setup work.

Learn to work in Metric System — millimeters, centimeters, meters, etc. It's a bit easier, more precise, and math is easier with metric. All but two or three countries are on the Metric System. Among countries not claiming to be metric, the USA is the only significant holdout. It doesn't pay off to be different. (Color vs. colour, grey vs. gray)

NOTE: I (Curt), think these are a recommendations are a little high, and you can get it a bit lower if your careful, and it's a quality ukulele, with good fret work, and there are no other issues beyond the action. However, too low, and you'll loose some volume as you will not be able to strum louder as the strings might buzz. It's a fine line and personal choice.

You might ask, Why doesn't a manufacture ship with low action?. Reason is it's a lot easier to lower the action than to raise the action. Plus, they have not idea who is going to get their instruments.

With fretless string instruments such as violins or cellos, intonation depends on the exact placement the musician's fingers pressing the strings against the instrument's fingerboard, as well as any pull or push the musician exerts on the string, either along the string's length or perpendicular to it.

For fretted string instruments, which is the ukulele, several factors affect fretted instrument intonation, including depth of the string slots in the nut, bridge saddle position, the position of the frets themselves, and the technique of the musician.

All of these can be addressed by a qualified luthier, technician or pro musician.

Or, you can try Compensated Nut MTS S.O.S. for Concert or Soprano Ukulele with Nylon Strings • This by HOSCO and really seems to really work. Checkout the the video on the HOSCO product page .

If the fret placement, all the notes along a string at each fret play in tune is correct you good to go. This can be checked with a quality tuner.

You can check the intonation of a ukulele by playing the harmonic at the twelfth fret and comparing it to the fretted note at the twelfth fret on all the string individually.

One thing that I have ran across as a music store owner and private music teacher with quite a few ukulele students and their instruments is — Intonation is a compromise on most ukuleles and on lower end ukuleles it is not even an option, you're not going to get it to play in tune beyond the third fret on most ukuleles under $50. So, the question, “Can I get a good, inexpensive ukulele that plays in tune — Basically, NO!. However, the Makala Dolphin and Shark ukuleles are actually quite good.

Several things can help. 1) Higher tensions, strings of better quality. 2) Have the nut adjusted, as most beginner ukuleles come with the nut slots far too high, causing the first few frets to play out of tune. 3) Don't press too hard, as that can cause the note to play out of tune.

• Relief — This is checking to see of the neck/fingerboard is right, all frets level and crowned properly, flat, and possibly a little relief.
• Action — Set the action of all the strings.
• Nut — This area takes the most expertise.
• Saddle — This area takes the most expertise.
• Intonation — Do this last. On ukulele it can be problematic to get it perfect. So, we accept a little imperfection.

• Remove material from the bottom of the saddle
• Double the amount of the 12th fret measure to remove. Example: if you wanted the reduce the action at the 12th frets by .8mm (2/64) you need to take .16mm of the the bottom of the saddle.