You wouldn't need to display those letters since this was used for Yamaha's musical instruments which only include 'A B C D E F G' No other letters are needed since they are only displaying notes/what type of note is being played
Yes, but not without some glaring limitations. The only way B and D can be displayed is in lowercase form because uppercase B and D look like the numbers 8 and 0 respectively. Also, the uppercase G looks like the number 6 and the lowercase g looks like the number 9 on a seven-segment digit. My Midland WR400 NOAA weather radio uses a 16-segment display to display the text line, which can display the letters of the alphabet much more faithfully, in addition to being able to implement a few different visual styles for the letters and numbers. I also own a Texas Instruments TI-30X II S and TI-83 scientific calculator that uses a 5x7 dot matrix as its alphanumeric text line, which even could have allowed the device to display text in other languages besides English with support for accented letters. As a kid, I had a toy ATM that used a whopping 18-segment display that allowed it to even be able to display the $ (United States dollar assumed), so it long begged the question of why the manufacturer couldn't have made a British model that displayed the £ or a European model that could have displayed the €.
Funny thing is, a segment for each of the letters is also only 7 segments. So technically, the following display *_ABCDEFG_* would be a more efficient design, theoretically.
This is used for displaying chords, so I'd expect on the right there will be "sus" and "maj" and whatnot. Having ABCDEFG just in a row would result in some glaring misalignment.