Mini

Mini - aka Baby, Midget, Piccolo, Pocket, Sopranino, Sopranissimo or Ukette
This is a scale length of less than 305mm, (12in) Usually around 280mm, (11in) and anything less than 200mm, (8in), is pretty much unplayable. (I know, I have a 171mm (6¾in) scale Ukulele! - as pictured below)

Some say this is not a proper scale though it has been around longer than Tenor or Baritone scales and is the only scale length to originate solely in Hawaii. It first appeared around 1914 as Jonah Kumalae introduced his Minis, (he came up with the size and he called them "Mini" so I shall do the same - after all we don't really call Concert Ukuleles Alto, because Concert was the original term). It was probably developed on the back of the very small, but playable, 5 fret demonstration models Kumalae was producing at the time. Other Hawaiian makers took up the scale and produced their own versions in the 'teens and 'twenties as did a few small mainland makers, but not the big Chicago and New York ones that came to dominate the trade.

Mario Maccaferri reintroduced it in the 'fifties with his Ukettes and some of the other plastic Ukulele manufacturers copied this sizing but it is debatable how much these were meant as serious instruments and how much they were aimed at small children. Maccaferri certainly claimed his Ukettes were meant to be serious instruments not just toys however the market ended up treating them just as toys.

Post millenium Ohana and Kala introduced the scale into their ranges as a serious instrument, (and started using the more proper sounding musical terms Sopranino and Sopranissimo to add to their "proper" instrument credentials), and it has taken off from there with a number of big Chinese manufacturers and top luthiers now producing them.

It should be noted that Mini Ukuleles, because of their size are genuinely harder to play and are not really for beginners, (the "its to small for my fat fingers" is a valid excuse here and not just someone whining when they realised effort was still involved learning to play!) They are also quite quiet acoustically and tonally less complicated than bigger models. These drawbacks are the reasons why the scale hasn't been very popular over the years

The tuning for a Mini is fairly flexible and there is no real "correct way", the reason for this is largely down to physics. Mostly Minis end up using the same strings and Sopranos and this means that if you tune g~C~E~A on the shorter scale length they are a bit slack for working properly, (and the intonation - how well it keeps in tune going up the fretboard - is poor), so you have to go a~D~F#~B or higher, as the scale length shortens (b~E~G#~C# or even higher). Of course playing with these high tunings can make the Mini even harder to play in some keys.

With its increase in popularity, (well availability anyway), the string maker Aquila have brought out a set of special extra thin Sopranino strings that enable you to tune your Mini to g~C~E~A but an octave higher than the normal tuning. However these strings are quite delicate and the scale length of your Mini needs to be less that 270mm (10½in - which is small!) for them to go this high, otherwise they will snap.