### Clue: Very soft pine for one backing possibly grand houses (10)
### Answer: PIANISSIMO 
 ### Explanation: Definition: Very soft
 [**Reversal of**(… backing) [MISS](pine for, as in "I miss you so!") + I(Roman numeral for "one")] **contained in**(… houses) PIANO(a model of which/possibly, is the grand).
Defn: …, as a direction in a music score.