You can choose between 20 and 30 Key Concertinas
You have a lot more options for keys when you are 30 but I recommend that you consider your preferred singing keys before making any decision. The Twenty button locks you very closely to the instrument’s home keys, so it is crucial to ensure that those are within your preferred range. Many church hymns are written using keys that make it difficult for me to sing. Although 20 buttons don’t have the same number of key pairs as 30 button concertinas, there should be some.
30 Button Concertinas
The 30+ button concertinas have chromatic keys throughout most of their range. Each key pair has c/g and Bb/f, Ab/Eb or g/d. There are keys that are more intuitive to learn, and it takes less time to figure out how to sing in the key you prefer. You might be better to consider the general range of the instrument. Higher pitched instruments might not be the best accompaniment for high voices, while a lower pitched instrument like a g/d may provide more notes that can complement your singing.
Try singing along to recordings of your favorite examples and trying to figure out their music. It might be hard to find the perfect concertina because some keys, such as G/D and C/G, are more common than others. However, hybrid makers can make a concertina that you prefer, with better concertinas. The Rochelle is a great starter instrument that can help you get started with singing. However, it’s not always the most expensive. Lachenal concertinas are a popular choice for people who sing to accompany their singing. They have a soft tone that matches the voice and cost less than the expensive Wheatstones, Jeffries, and Crabbs. Although they can be noisy, it is not a problem when singing is being performed.
I hope that you find something you love. A concertina is a great instrument for playing shanty or ballads.
Budget for 30 Key Concertina
A 30 is a good choice if your budget allows. A 30 will give you a wider range of chord voicings for song accompaniment. A 20-button can be used for accompaniment. I remember using a Lachenal 20 key G/D to accompany Miss Otis Regrets. They are, however, very limited.
You should also consider what keys you prefer singing in. This will influence your choice of instrument in C/G and G/D. A 31-key, i.e. Bellamy-sounding instrument may be the best option if you want to achieve that Bellamy sound. With a thumb “drone note”.
20 Key Concertina
To put it in perspective, concertina accompaniment to my own singing began with a 20-button East German concertina. It was easy to learn, and the chords and arpeggios that you need to accompany your singing in the two home keys were very intuitive. I should also mention that I am a baritone and can sing most folk songs and shanties in C major. Hymns in G major are difficult for me to sing. Although I don’t know your voice quality, I can tell you that C/G would work for you if you have a higher pitch than mine.
Later I purchased a C/G Anglo 30-button C/G Anglo and kept my accompaniments in C and G. However, I discovered that I was able to create more complex arrangements with 30 buttons than I could with 20 buttons. I realized this and improved my accompaniments.
If you would like to check out the Irish 30 key Concertina Manufacturers, Check out their site.