For instance, the name HAYDN is mapped to the note sequence BADDG in Ravel's "Menuet sur le nom d'Hadyn". And the name CLARA is mapped to CBAA in Schumann's Piano concerto. Why is that the case? Is there a standard for mapping names to notes? If I want to map the name SCRIABIN to notes, what would the notes be?
The concept has been used for many centuries - often spuriously in my view - and Bach was probably one of the luckier ones. BACH translates directly into musical notes, as fortuitously the German notation uses 'B' for B♭ and 'H' for B♮. John Cage was also fortunate and wrote Cage Dead as one of his audible pieces.
It's akin to 'personalised number plates' in UK, where car owners use 5 as S, 8 as B, 1 as I and 0 as O for example, spelling out 'names'. As in JAMIE, PATSY and SINGH. A bit of fun, really!
German Es and As (E♭ and A♭) have been used by some composers to spell out motifs with their names, some more successfully than others.
There is a 'French system' which puts letters in a box:
A B C D E F G
H I J K L M N
O P Q R S T U
V W X Y Z
And letters which don't exist musically can be found vertically underneath the genuine 7 letters. Thus G would represen N, or U, D would represent K, R or Y.
CRYPTOGRAM is the key word.
In English, one has two vowels (A,E) and 5 consonants (B,C,D,F,G) so you get what can be spelled with these letters. In German one gets H (and perhaps Es, As, etc.); I don't know other languages that well. (Use the syllabus, do, re, mi, fa, sol, la, ti, perhaps?) German gets to have BACH and English gets CABBAGE.