It seems, that rosegarden forces gui font to be Sans. On my system default sans seems to be droid. In qt5, with russian locale, russian bold letters are drawen by some kind of Courier New. Regular font is still Sans, and this bug seems to affect all qt5 stuff - i noticed it first time in Converseen. After i changed to Deja Vu, and yet later began to search for more interesting fonts (up to tomorrow i had Exo), problem disappeared. For qt5 config i use qt5ct. Today i assidentally discovered font pair, which imho looks awesome with programs like MuseScore and Rosegarden. I don't know, is it intended to force some specific font... so i want to propose as variant to use any Serif font. Last time i tried CMU fonts: http://cm-unicode.sourceforge.net/ CMU has very interesting (imho) serif variants (though simple sans style also presents). Especially i want to note: - Contrete - as easy to read as any Serif, but more interesting, than its own CMU Serif - i.e., it looks much sharper. - Pair of two fonts: - - CMU Serif Upright Italic: regular ornamental font - - CMU Classical Serif: former's italic kind (both have bold kinds) And i would note, there is some mess in names. Thus, upright italic is not really italic (just looks ornamental), while simple classical looks like "CMU Serif Upright Italic" Italic :). Would be better for them, of course to be in one "CMU Classical" font, providing as usually - 4 kinds. This of course, is for aesthetes :) Screenshot with musescore, with CMU Classical font: https://musescore.org/sites/musescore.org/files/2018-03/musescore_2018-03-1… I guess (it is still my imho+taste), all these Serif/Concrete/Classical fonts would look much better in rosegarden. Can't tell about other (even musical) software, but for now i made "CMU Serif Upright Italic" default font - in qt5ct, desktop appearance settings (xfce), and now trying to get for qt4. It exactly works with qjackctl and musescore. ________________________________ About qtractor, if Rui Nuno Capella reads, there are few places, where, where sans is forced: - clock on toolbar, - files list and track list use sans italic. I don't know, is it sideback of setting to italic, but track list ruler uses regular sans. But still, BPM display, near of clock, followes system font.