Hi Jonathan,
As a workaround you can use :
\version "2.19.22"
\markup\concat{ B \fontsize #-2 ARTHOLOMÄUS }
However, in the past I used a fairly old code, slightly adapted here :
\version "2.19.45"
%% original code by N. Sceaux
#(use-modules (ice-9 regex))
#(define-public string-upper-case #f)
#(define accented-char-upper-case? #f)
#(define accented-char-lower-case? #f)
#(let ((lower-case-accented-string "áàâäǎăāãåąæǣćĉčçďđðéèêëěĕēęəĝğģĥħíìîïǐĭīĩįĵķĺŀľļłńňñóòôöǒŏōõǫőøœŕřśŝšşťţþúùûüǔŭūųǘǜǚŵýŷÿȳźž")
(upper-case-accented-string "ÁÀÂÄǍĂĀÃÅĄÆǢĆĈČÇĎĐÐÉÈÊËĚĔĒĘƏĜĞĢĤĦÍÌÎÏǏĬĪĨĮĴĶĹĿĽĻŁŃŇÑÓÒÔÖǑŎŌÕǪŐØŒŔŘŚŜŠŞŤŢÞÚÙÛÜǓŬŪŲǗǛǙŴÝŶŸȲŹŽ"))
(define (group-by-2 chars result)
(if (or (null? chars) (null? (cdr chars)))
(reverse! result)
(group-by-2 (cddr chars)
(cons (string (car chars) (cadr chars))
result))))
(let ((lower-case-accented-chars
(group-by-2 (string->list lower-case-accented-string) (list)))
(upper-case-accented-chars
(group-by-2 (string->list upper-case-accented-string) (list))))
(set! string-upper-case
(lambda (str)
(define (replace-chars str froms tos)
(if (null? froms)
str
(replace-chars (regexp-substitute/global #f (car froms) str
'pre (car tos) 'post)
(cdr froms)
(cdr tos))))
(string-upcase (replace-chars str
lower-case-accented-chars
upper-case-accented-chars))))
(set! accented-char-upper-case?
(lambda (char1 char2)
(member (string char1 char2) upper-case-accented-chars string=?)))
(set! accented-char-lower-case?
(lambda (char1 char2)
(member (string char1 char2) lower-case-accented-chars string=?)))))
#(define-markup-command (caps layout props text) (markup?)
(define (string-list->markup strings lower)
(let ((final-string (string-upper-case
(apply string-append (reverse strings)))))
(if lower
(markup #:fontsize -2 final-string)
final-string)))
(define (make-small-caps rest-chars currents current-is-lower prev-result)
(if (null? rest-chars)
(make-concat-markup (reverse! (cons (string-list->markup
currents current-is-lower)
prev-result)))
(let* ((ch1 (car rest-chars))
(ch2 (and (not (null? (cdr rest-chars))) (cadr rest-chars)))
(this-char-string (string ch1))
(is-lower (char-lower-case? ch1))
(next-rest-chars (cdr rest-chars)))
(cond ((and ch2 (accented-char-lower-case? ch1 ch2))
(set! this-char-string (string ch1 ch2))
(set! is-lower #t)
(set! next-rest-chars (cddr rest-chars)))
((and ch2 (accented-char-upper-case? ch1 ch2))
(set! this-char-string (string ch1 ch2))
(set! is-lower #f)
(set! next-rest-chars (cddr rest-chars))))
(if (or (and current-is-lower is-lower)
(and (not current-is-lower) (not is-lower)))
(make-small-caps next-rest-chars
(cons this-char-string currents)
is-lower
prev-result)
(make-small-caps next-rest-chars
(list this-char-string)
is-lower
(if (null? currents)
prev-result
(cons (string-list->markup
currents current-is-lower)
prev-result)))))))
(interpret-markup layout props
(if (string? text)
(make-small-caps (string->list text) (list) #f (list))
text)))
%%Tests:
\markup \caps "A a Á á À à Â â Ä ä Ǎ ǎ Ă ă Ā ā Ã ã Å å Ą ą Æ æ Ǣ ǣ"
\markup \caps "B b"
\markup \caps "C c Ć ć Ĉ ĉ Č č Ç ç"
\markup \caps "D d Ď ď Đ đ Ð ð"
\markup \caps "E e É é È è Ê ê Ë ë Ě ě Ĕ ĕ Ē ē Ę ę Ə ə"
\markup \caps "F f"
\markup \caps "G g Ĝ ĝ Ğ ğ Ģ ģ"
\markup \caps "H h Ĥ ĥ Ħ ħ"
\markup \caps "I i Í í Ì ì Î î Ï ï Ǐ ǐ Ĭ ĭ Ī ī Ĩ ĩ Į į"
\markup \caps "J j Ĵ ĵ"
\markup \caps "K k Ķ ķ"
\markup \caps "L l Ĺ ĺ Ŀ ŀ Ľ ľ Ł ł"
\markup \caps "M m"
\markup \caps "N n Ń ń Ň ň Ñ ñ"
\markup \caps "O o Ó ó Ò ò Ô ô Ö ö Ǒ ǒ Ŏ ŏ Ō ō Õ õ Ǫ ǫ Ő ő Ø ø Œ œ"
\markup \caps "P p"
\markup \caps "Q q"
\markup \caps "R r Ŕ ŕ Ř ř"
\markup \caps "S s Ś ś Ŝ ŝ Š š Ş ş ß"
\markup \caps "T t Ť ť Ţ ţ Þ þ"
\markup \caps "U u Ú ú Ù ù Û û Ü ü Ǔ ǔ Ŭ ŭ Ū ū Ų ų Ǘ ǘ Ǜ ǜ Ǚ ǚ"
\markup \caps "V v"
\markup \caps "W w Ŵ ŵ"
\markup \caps "X x"
\markup \caps "Y y Ý ý Ŷ ŷ Ÿ ÿ Ȳ ȳ"
\markup \caps "Z z Ź ź Ž ž"
HTH,
Pierre