Filed Pursuant to Rule 424(b)(3)

Registration No. 333-155800

May 2011 Performance Update

The Frontier Fund Supplement Dated May 31, 2011 to Prospectus Dated April 30, 2011.

The Frontier Fund Class 1 Original

T H E  F R O N T I E R  F U N D ’ S  G O A L : To provide you – the investor – with a managed futures product that, over the long term, provides attractive returns, reduces volatility, and improves the overall performance of your investment portfolio.

May performance for the various Series of The Frontier Fund is detailed below:*

The Frontier Fund Class 1 Original	May 31, 2011 MTD	May 31, 2011 YTD		NAV / Unit
Balanced Series-1	-2.66%	1.64%	$	134.11
Balanced Series-1a	-2.76%	1.20%	$	117.75
Berkeley/Graham/Tiverton Series-1	-7.48%	-5.37%	$	104.54
Currency Series-1	-2.85%	-5.03%	$	75.11
Long/Short Commodity Series-1	-4.00%	12.67%	$	149.55
Winton/Graham Series-1	-5.03%	-1.12%	$	118.49
Winton Series-1	-2.61%	1.38%	$	136.90
Long Only Commodity Series-1	-5.21%	3.36%	$	97.27
Managed Futures Index Series-1	-6.68%	-6.77%	$	109.97

Additional information, including monthly rates of return, concerning the aforementioned Series and the Trading Advisor(s) is contained in the Prospectus and the respective Series Appendix to the Prospectus.

* The above table sets forth the actual performance for the Class and Series as of May 31, 2011. Actual gross trading performance (gross realized and unrealized gain/loss before deduction for trading commissions and fees, management fees, any other expense, and before addition of interest income) is adjusted for the trading expenses, management fees, initial service fees, on-going service fees, and interest income of the applicable Series.

THIS INSERT MUST BE ACCOMPANIED OR PRECEDED BY THE CURRENT PROSPECTUS OF THE FRONTIER FUND

PAST PERFORMANCE IS NOT INDICATIVE OF FUTURE RESULTS

THE FRONTIER FUND BALANCED SERIES—1

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	54,515,602.43
Unrealized trading gain/(loss)		(58,359,941.27	)
Less: commissions		(283,851.91	)
Less: FCM fees		(94,017.38	)
Foreign currency gain/(loss)		(1,179,440.88	)
Interest income		48,208.24
Total Income		(5,353,440.77	)
EXPENSES
Management fees		162,771.18
Incentive fees		936,109.99
Broker service fees		628,576.22
Total Expenses		1,727,457.39
Net Income (Loss)	$	(7,080,898.16	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		1,934,899.25057		$	266,580,632.91			137.77
Current month additions		446.10498			60,155.05
Current month redemptions		(212,418.68288	)		(28,490,278.30	)
Net Income (loss) for current month					(7,080,898.16	)
Net Asset Value, end of current month		1,722,926.67267		$	231,069,611.50			134.11
Monthly rate of return								-2.66	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Balanced Series 1

THE FRONTIER FUND BALANCED SERIES—1a

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	935,997.99
Unrealized trading gain/(loss)		(1,000,337.09	)
Less: commissions		(4,860.59	)
Less: FCM fees		(1,615.00	)
Foreign currency gain/(loss)		(19,891.04	)
Interest income		4,772.88
Total Income		(85,932.85	)
EXPENSES
Trading Fee		8,526.37
Management fees		2,800.02
Incentive fees		16,295.63
Broker service fees		10,798.62
Total Expenses		38,420.64
Net Income (Loss)	$	(124,353.49	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		38,926.18862		$	4,713,908.10			121.10
Current month additions		3.91381			463.64
Current month redemptions		(5,509.73969	)		(654,676.04	)
Net Income (loss) for current month					(124,353.49	)
Net Asset Value, end of current month		33,420.36274		$	3,935,342.21			117.75
Monthly rate of return								-2.76	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Balanced Series 1a

THE FRONTIER FUND BERKELEY/GRAHAM/TIVERTON SERIES—1

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	(1,994,157.35	)
Unrealized trading gain/(loss)		(1,850,709.75	)
Less: commissions		(53,495.18	)
Less: FCM fees		(21,529.21	)
Foreign currency gain/(loss)		(13,105.48	)
Interest income		3,615.32
Total Income		(3,929,381.65	)
EXPENSES
Management fees		170,268.63
Incentive fees		(167,833.24	)
Broker service fees		126,698.43
Total Expenses		129,133.82
Net Income (Loss)	$	(4,058,515.47	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		491,184.47766		$	55,497,464.42			112.99
Current month additions		59.64340			6,268.65
Current month redemptions		(50,184.11798	)		(5,338,464.20	)
Net Income (loss) for current month					(4,058,515.47	)
Net Asset Value, end of current month		441,060.00308		$	46,106,753.40			104.54
Monthly rate of return								-7.48	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Berkeley/Graham/Tiverton Series 1

THE FRONTIER FUND CURRENCY SERIES—1

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	5,284.47
Unrealized trading gain/(loss)		(139,081.06	)
Less: FCM fees		(2,334.31	)
Interest income		2,595.25
Total Income		(133,535.65	)
EXPENSES
Management fees		4,173.91
Incentive fees		—
Broker service fees		13,830.21
Total Expenses		18,004.12
Net Income (Loss)	$	(151,539.77	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		73,433.47318		$	5,677,477.21			77.31
Current month additions		64.22627			4,976.14
Current month redemptions		(5,830.09545	)		(448,486.50	)
Net Income (loss) for current month					(151,539.77	)
Net Asset Value, end of current month		67,667.60400		$	5,082,427.08			75.11
Monthly rate of return								-2.85	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Currency Series 1

THE FRONTIER FUND LONG/SHORT COMMODITY SERIES—1

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	2,782,171.51
Unrealized trading gain/(loss)		(3,692,350.87	)
Less: commissions		(10,629.98	)
Less: FCM fees		(9,371.08	)
Foreign currency gain/(loss)		1,874.72
Interest income		39,713.36
Total Income		(888,592.34	)
EXPENSES
Management fees		103,096.28
Incentive fees		21,582.97
Broker service fees		55,142.93
Total Expenses		179,822.18
Net Income (Loss)	$	(1,068,414.52	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		158,814.85639		$	24,740,636.91			155.78
Current month additions		53.65388			7,791.16
Current month redemptions		(30,354.52217	)		(4,461,340.87	)
Net Income (loss) for current month					(1,068,414.52	)
Net Asset Value, end of current month		128,513.98810		$	19,218,672.68			149.55
Monthly rate of return								-4.00	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Long/Short Commodity Series 1

THE FRONTIER FUND WINTON/GRAHAM SERIES—1

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	(775,351.90	)
Unrealized trading gain/(loss)		(1,384,000.26	)
Less: commissions		(17,958.81	)
Less: FCM fees		(15,250.00	)
Foreign currency gain/(loss)		1,689.07
Interest income		10,840.03
Total Income		(2,180,031.87	)
EXPENSES
Management fees		103,495.84
Incentive fees		(353,957.29	)
Broker service fees		89,537.41
Total Expenses		(160,924.04	)
Net Income (Loss)	$	(2,019,107.83	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		315,070.96178		$	39,311,007.42			124.77
Current month additions		89.60113			10,291.28
Current month redemptions		(31,023.50552	)		(3,635,490.28	)
Net Income (loss) for current month					(2,019,107.83	)
Net Asset Value, end of current month		284,137.05739		$	33,666,700.59			118.49
Monthly rate of return								-5.03	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Winton/Graham Series 1

THE FRONTIER FUND WINTON SERIES—1

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	(396,882.27	)
Unrealized trading gain/(loss)		(914,767.42	)
Less: commissions		(2,333.42	)
Less: FCM fees		(17,964.55	)
Foreign currency gain/(loss)		(932.94	)
Interest income		30,939.35
Total Income		(1,301,941.25	)
EXPENSES
Management fees		87,307.94
Incentive fees		(296,747.46	)
Broker service fees		105,862.85
Total Expenses		(103,576.67	)
Net Income (Loss)	$	(1,198,364.58	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		314,150.22535		$	44,159,428.65			140.57
Current month additions		152.85780			20,371.92
Current month redemptions		(19,878.39479	)		(2,674,202.41	)
Net Income (loss) for current month					(1,198,364.58	)
Net Asset Value, end of current month		294,424.68836		$	40,307,233.58			136.90
Monthly rate of return								-2.61	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Winton Series 1

THE FRONTIER FUND LONG ONLY COMMODITY SERIES—1

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	(170,317.53	)
Unrealized trading gain/(loss)		886.70
Less: commissions		—
Less: FCM fees		(1,202.08	)
Foreign currency gain/(loss)		—
Interest income		5,238.18
Total Income		(165,394.73	)
EXPENSES
Management fees		3,371.46
Incentive fees		—
Broker service fees		4,737.88
Total Expenses		8,109.34
Net Income (Loss)	$	(173,504.07	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		31,829.15472		$	3,265,929.12			102.61
Current month additions		1.03879			96.70
Current month redemptions		(8,775.54505	)		(850,083.73	)
Net Income (loss) for current month					(173,504.07	)
Net Asset Value, end of current month		23,054.64846		$	2,242,438.02			97.27
Monthly rate of return								-5.21	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Long Only Commodity Series 1

THE FRONTIER FUND MANAGED FUTURES INDEX SERIES—1

STATEMENT OF INCOME (LOSS)

FOR THE MONTH ENDED

May 31, 2011

(Unaudited)

	Current Period
INCOME
Realized trading gain/(loss)	$	(28,400.95	)
Unrealized trading gain/(loss)		(25,373.68	)
Less: commissions		(128.91	)
Less: FCM fees		(319.64	)
Foreign currency gain/(loss)		59.75
Interest income		1,361.00
Total Income		(52,802.43	)
EXPENSES
Management fees		1,504.48
Incentive fees		—
Broker service fees		1,246.50
Total Expenses		2,750.98
Net Income (Loss)	$	(55,553.41	)

STATEMENT OF CHANGES IN NET ASSET VALUE

	Units			Dollars			$'s per unit
Net Asset Value, end of prior month		7,141.97090		$	841,621.42			117.84
Current month additions		—			—
Current month redemptions		(1,006.98245	)		(111,385.86	)
Net Income (loss) for current month					(55,553.41	)
Net Asset Value, end of current month		6,134.98845		$	674,682.15			109.97
Monthly rate of return								-6.68	%

To the best of my knowledge and belief, the information

contained in this statement is accurate and complete

/s/ S. Brent Bales

S. Brent Bales, Chief Accounting Officer of the Managing Owner

Equinox Fund Management LLC

1775 Sherman Street, Suite 2500

Denver, Colorado 80203

On Behalf of the Frontier Fund—Managed Futures Index Series 1