Solution to 23A has been deliberately left unsolved and is to be answered only by a non-regular / novice commenter, with proper annotation. Those who have answered earlier in the week, please give others a chance.
Open for anyone to answer, if not solved by 1 PM.
ACROSS
1 Hat with bit of fur sticking in was abandoned (6) BEREFT {BERE{Fur}T}
4 Soy dish temperature's what again? (6) TEMPEH {TEMP}{EH}
8 Bachelor (American) can be seen following Sunday school's concert band member (4,3) BASS SAX {BA}{AX} over {SS'S}
14 Guy at party arrived following lady - one with strings attached (8) MANDOLIN {MAN}{DO} with {IN}<=>{L}
18 Woman taken in by bogus instrument (5) SHAWM {SHA{W}M}
23 Hospital department's clipped roster holding small order for dispenser (7) ?E?O?O?
26 Break from tax after refinance got voided (6) RECESS {CESS}<=>{Re...cE}
DOWN
1 Find fault with boring book at the beginning (5) BLAME{LAME}<=>{B}
2 Pressure European Community to join others with tact (7) RESPECT {RES{P}{EC}T}
7 Music maker - softly yet surprisingly dismissed immunotherapy treatment (9) HARMONIUM IMMUNOtHeRApy
13 Holding beer, gasp working with an instrument (9) PANTALEON {ALE} in {PANT}{ON}
17 Mountain goat's weapon can be an instrument (7) ALPHORN {ALP}{HORN}
21 Unpopular instrument - a musical instrument? (5) VIOLA {VIOL}{A}
Reference List
Bachelor = B, American = E, Sunday = S, School = S, Prince = P, Party = DO, Lady = L, Reading = R, Woman = W, University = U, Book = B, Pressure = P, Energy = E, Out = O, Time = T, Softly = P, Hard = H, Leaf = L, Humidity = H