Times Jumbo 1,007

[Donaldinho]

13A Recurring music phrase - M?t?o
17A Very able musician - S?g?t ?e?d?r
35A Boring tool:cocktail - ?i?l?t

[emeritus]

17a Sight reader

[emeritus]

35a Gimlet

[bibblebub]

13a) motto

[dannyk13]

13a.Motif
17a.Sight reader
35a.Gimlet

[bibblebub]

definitely motto to fit with 3d

[dannyk13]

Motto is not a recurring theme in any dictionary I have checked.

[Mamyalynne]

mot·to
noun /ˈmätō/ 
mottoes, plural; mottos, plural

A short sentence or phrase chosen as encapsulating the beliefs or ideals guiding an individual, family, or institution
- the school motto, “Serve and obey”
- he soon adopted the motto “work hard and play hard.”

A phrase that recurs throughout a musical work and has some symbolic significance

[Lie-in King]

Danny - http://www.thefreedictionary.com/motto (2nd list, no 5)