How can I tell if the edition of my music score is reliable? - piano

"Urtext" (German for "original text") editions are generally the closest to the composer's intentions. Since centuries have passed, sometimes it is difficult to tell whether an Urtext edition is 100% philological, but you can follow these tips. Scores with many indications (fingerings, staccatos, legatos, pedals) of pieces of the 17th-18th century, are quite surely not an Urtext. For pieces not written for piano (i.e. Harpsichord), pedal signs are not original because the pedal is a later invention. This applies for Bach and his contemporaries. I don't remember of any staccato in Bach's scores. Features such as legatos, during the baroque and classical era, tend to stay within a bar, as they generally represented the bow of the violin. Longer legatos are more of a romantic feature (Beethoven, Chopin). For some major works, like Beethoven's piano Sonatas, publisher G. Henle Verlag is philologically very good. For Debussy, Durand has a very good reputation.