The phrase to pull out all the stops, and its variants, mean: to do everything possible to achieve a result or effect.
This phrase occurs, for example, in Truss: PM is fully co-operating with the Met’s partygate probe, by David Bond, Deputy Political Editor, published in the Evening Standard (London, England) of Tuesday 15th February 2022:
BORIS JOHNSON is “fully co-operating” with the Metropolitan Police’s probe into “partygate”, Foreign Secretary Liz Truss said today.
The Prime Minister has until Friday to respond to a questionnaire sent to him by detectives investigating at least 12 parties and gatherings in Downing Street and Whitehall while Covid lockdown restrictions were in place.
With Mr Johnson still facing the possibility of a no confidence vote if the Met issues him a fixed penalty notice for breaking lockdown rules, Ms Truss insisted today that he was not being distracted from other important issues, notably the growing crisis over Ukraine.
“He is fully co-operating with the police inquiry,” Ms Truss told Sky News. “But there is a very serious situation at present with Russia and Ukraine and he is focused on that.
“He will be chairing a meeting of Cobra later this morning to make sure we are really pursuing the diplomacy… that we are pulling out all the stops on that at the same time as preparing for the worst and making sure we are in the best possible position to respond.”
The phrase to pull out all the stops alludes to pulling out all the stops of an organ in order to produce a full and thrilling sound. This phrase is used literally, for example, in the account of a banquet that took place in the Town-hall of Birmingham, Warwickshire, England, during the thirty-fifth meeting of the British Association for the Advancement of Science—account published in The Daily News (London, England) of Saturday 9th September 1865:
Such was the clatter of tongues, it was indeed a very Babel. Some idea of the power of the organs of speech (after dinner) may be formed when I say that the enormous organ of the hall was absolutely drowned at times in the storm of chatter that filled the hall. Poor Mr. Stimpson, the organist, had to revenge himself for the loss of all his fine piano passages by pulling out all the stops, and firing a concentrated broadside of all the tiers of his diapason.
The earliest figurative uses of the phrase to pull out all the stops and variants that I have found are as follows, in chronological order—several texts pun on two meanings of the noun organ, which are a musical instrument and a periodical:
1-: From the Preface to Essays in Criticism (London and Cambridge: Macmillan and Co., 1865), by the British poet and critic Matthew Arnold (1822-1888):
My design in writing this Preface […] was, after apologising to Mr. Wright […], to beg him and others to let me bear my own burdens, without saddling the great and famous University, to which I have the honour to belong, with any portion of them. […] Proud as I am of my connection with the University of Oxford, I can truly say, that, knowing how unpopular a task one is undertaking when one tries to pull out a few more stops in that powerful, but at present somewhat narrow-toned organ, the modern Englishman, I have always sought to stand by myself, and to compromise others as little as possible.
2-: From the Coventry Standard (Coventry, Warwickshire, England) of Friday 11th September 1868:
In our issues of August 28th and 29th there appeared a letter, signed “A Lover of the Truth,” urging the setting apart of certain days prior to the General Election, in which the Protestant people of this nation should offer up public and private prayers to God, that He would so overrule and direct the course of events, as to save the country from the domination of Romanism, and preserve to it the religious privileges it has so long enjoyed.—We inserted the letter, as matter of course, seeing in it no sufficient reason for rejecting it. On the following Wednesday, Sept. 2, our contemporary, the local “acknowledged organ of the Nonconformist body in Coventry,” fancying that, from the fact of the letter appearing in our columns, there must “Toryism” at the bottom of it, manifested decided symptoms of one of its common fits of rabid mania, and thus broke out:—
“Last week, a singular letter appeared in our Tory contemporary. Now, we think that the invitation to Godly people to ‘pray for our country’ at the present moment is a very proper one, and we only wonder why this devout correspondent should have sent his request to the Tory journal exclusively.”
This pious Nonconformist organ then goes on to pull out all its “stops,” and to perform great thunder, which it concluded by a virtuous expression of “scorn” for the letter which should suggest the idea of prayer, and throw out such a hint through “the Tory journal exclusively.”
3-: From Sir Oracle and His Bark, published in The Brooklyn Sunday Sun (Brooklyn, New York, USA) of Sunday 2nd July 1876:
Dr. Barnes, ex-peddler of pills and plasters, finds comfort for Tilden’s nomination in the unwitting company which John Kelly keeps with him. […]
Still though if report be true, he is out of pocket by exactly what it costs a Major General on a holiday to make such a trip as Slocum’s to St. Louis, Barnes is soothed into forgetfulness of his extravagance by seeing Kelly flattened out rather more thoroughly than himself. And this is why Barnes, instead of pulling out all his stops and playing a characteristic fantasia of idiotic discords on his “organ,” breaks out only into a wild but drowsy strain of subdued commentation and not into an outburst of chagrin.
Having many an empty column to spare, the Doctor gives a whole one to the monody.
4-: From The Feeling of the Country, published in the Wilts and Gloucestershire Standard (Cirencester, Gloucestershire, England) of Saturday 21st December 1878:
We do not grudge the Liberals their success at Bristol. It is unquestionably a very important constituency, and if we had won the seat no doubt we should have made a fine noise upon the political trumpet […]. The London papers have made a great deal more of it than the facts of the case will warrant. […] The Radical organs are quite right in pulling out all their stops and making as much noise as they can over the event—they have not had many triumphs for the last few years—but it really does not mean much after all.
5-: From The Daily Examiner (San Francisco, California, USA) of Wednesday 3rd September 1879:
Bull-Dosing in Massachusetts.
Whenever the Republican party gets hard up for a sensation it hauls out a fresh batch of bull-dosing testimony; whereupon the party organists pull out all the stops, and wake the echoes with their oft-strained strains. The idea used to be to show that Federal troops were needed in the South. Now the idea is to show that certain citizens are denied their rights, wherefore the Congressional representation of the South ought to be cut down, and the good people of the North ought to vote the Republican ticket. We are used to Southern bull-dosing as recorded by the organs, remarks the Philadelphia Chronicle, have it labeled at about its worth, and can afford to let it rest where it is, relying on the organs to sound the dread alarm if the situation should become more sanguinary.