Solo parts
If you scan a solo part for a transposing instrument in PlayScore it will play in the written key by default. To hear the music at concert pitch you should set the transposition on the Play and MIDI settings screen. For example for a Bb clarinet set the transposition to -2.
Tip: selecting an instrument from the dropdown only affects the timbre. It does not set a transposition.
Music with an accompaniment or ensemble music
If your music has instruments with different key signatures, for example Bb clarinet and piano, turn on Auto-transpose under the Document settings. PlayScore will then adjust everything so that the instruments sound right together.
In some cases PlayScore can pick up information from instrument name text to the left of a staff. For example, the instrument name can tell PlayScore that a double bass plays an octave lower, or a picadillo an octave higher than the written key
To make PlayScore pick up transposing information from instrument names in the score turn on Lyrics and text in the Document settings.
For more information on transposing instruments, especially ensembles involving transposing brass, see Transposing instruments and transposition.